《人工晶体学报》 Vol.35

2006年第4期 摘要


浸没籽晶法生长La2CaB10O19单晶的研究

景芳丽1,2, 吴以成1, 傅佩珍1,祖延雷1,2

(1.中国科学院理化技术研究所,北京人工晶体研究发展中心,北京 100080; 2.中国科学院研究生院,北京 100039)

摘要:采用浸没籽晶法以CaOLi2OB2O3为助熔剂生长出La2CaB10O19单晶。籽晶的方向对晶体质量有较大的影响。晶体结构导致生长出的晶体均呈现板状外形,并且容易沿(001)面解理;捆绑晶体的铂丝嵌入晶体加剧了晶体的解理。然而解理和铂丝嵌入对不同方向籽晶生长出晶体的质量影响各不相同,对于晶体生长过程溶质输运的影响也不相同,实验发现,[101]方向为本实验条件下最佳的晶体生长方向。 关键词:La2CaB10O19晶体;助熔剂;解理 近化学计量比铌酸锂晶体组分测定与缺陷观察

黄庆捷1, 王继扬2

(1.山东大学信息科学与工程学院,济南 250100; 2.山东大学晶体材料国家重点实验室,济南250100)

摘要:采用助熔剂提拉法生长得到近化学计量比LiNbO3晶体。用多种方法测定了晶体组分,测试表明生长得到的晶体中[Li2O]含量为49.80%摩尔分数;对晶体缺陷的研究表明晶体质量有待提高,并分析了晶体中出现包裹物的原因。 关键词:LiNbO3;近化学计量比;缺陷;组分测定;化学腐蚀

采用溶胶凝胶前驱物制备氮化镓纳米晶体

邱海林,王迎春,许光燕,曹传宝 (北京理工大学材料科学研究中心,北京 100081)

摘要:采用溶胶凝胶法制备的前驱物进一步在900℃,氨气气氛中氮化得到粒径相对均匀、平均粒径为11.2nm的六方相氮化镓纳米晶体。XRD, HRTEM, SAED, EDS, FTIR被用于表征产物的微结构及组成。室温光致发光光谱显示产物位于3.46eV的带边发光峰和从 2.6~3.2eV 的宽的发光带。产物可直接用于制备氮化镓量子点复合材料和制备高质量的一维氮化镓晶体。 关键词:氮化镓;溶胶凝胶;光致发光

LaCl3:Ce3+晶体生长用无水氯化镧的制备

陈红兵1 ,周昌勇1 ,杨培志2 ,蒋成勇1 ,潘建国1

(1.宁波大学固体材料化学研究所, 新型功能材料及其制备科学国家重点实验室培育基地,宁波 315211; 2. 昆明物理研究所,昆明 650223 )

摘要:本文报道了LaCl3:Ce3+晶体生长用无水氯化镧的氯化焙烧脱水制备方法。应用差热/热重分析研究了LaCl3·7H2O的脱水过程,以寻求避免发生水解反应的有效途径;以LaCl3·7H2O为初始原料,采用氯化氢保护下的焙烧脱水处理进行无水氯化镧的制备,通过系列实验掌握了氯化焙烧脱水处理的最佳工艺条件;为验证所制备无水氯化镧的纯度,采用该原料进行了LaCl3:Ce3+单晶生长。结果表明,在氯化焙烧脱水处理过程中,保持通入足量干燥氯化氢气体,控制焙烧温度于220~230℃,经过6~7h焙烧处理,能够制备出较高纯度的无水氯化镧,所获原料可成功地用于生长无色透明的LaCl3:Ce3+单晶。 关键词:无水氯化镧;焙烧;脱水;晶体生长

退火对Nd,Cr:GSGG激光晶体吸收光谱的影响

孙敦陆,张庆礼,江海河,殷绍唐 (中国科学院安徽光学精密机械研究所晶体材料研究室,合肥 230031)

摘要:本文应用吸收光谱法,对提拉法生长的Nd,Cr:GSGG晶体在不同气氛下退火后的光谱变化进行了研究。氧化气氛下退火后的吸收光谱中,在1μm处出现了由于晶体中存在Cr4+离子所引起的两个吸收带,被称为1μm吸收损失。还原气氛(CO和H2)下退火后的吸收光谱中,在1μm处的吸收带基本消失,这对于提高激光效率是非常有利的。此外,在642nm处的吸收带强度有一定的减弱。这些数据对于晶体后处理工艺的改进和激光器设计具有重要的参考价值。 关键词:Nd,Cr:GSGG晶体; 还原气氛; 退火; 吸收损失

数值模拟自然对流对直拉单晶硅的影响

宇慧平1, 隋允康1,王敬2, 安国平1

(1. 北京工业大学机电学院, 北京 100022, 2. 北京有色金属研究总院,北京 100088)

摘要:在直拉单晶硅生长的过程中,自然对流对晶体界面的形状、温度场及应力分布影响很大。本文采用二维模型对熔体内自然对流对单晶硅的影响作了数值模拟,在低雷诺数时采用层流模型,高雷诺数时采用紊流模型,Gr的变化范围从3×106到3×1010,这样涵盖了从小尺寸到大尺寸的直拉单晶硅生长系统。数值结果表明熔体的流动状态不仅与熔体的Gr有关,还与熔体高度和坩埚半径的比值密切相关。当Gr>108时,熔体内确实存在紊流现象,层流模型不再适合, 随着Gr的增大,紊流现象加剧,轴心处的等温线变得更为陡峭,不利于晶体生长。 关键词:直拉单晶硅;自然对流;数值模拟ADP及KDP晶体纵向压电系数d33的计算及其验证

王越1,常新安2,刘国庆1,蒋毅坚3

(1.北京工业大学应用数理学院,北京100022;2.北京工业大学材料学院,北京100022;3.北京工业大学国家产学研激光技术中心,北京 100022)

摘要:ADP(磷酸二氢铵)和KDP(磷酸二氢钾)晶体都属于42m点群,是20世纪早期的著名压电晶体,具有易于大尺寸生长的优点。但它们在主轴坐标系中只有厚度切变压电系数(d14, d36),没有纵向压电系数(d33,k33),而这种纵向压电效应在实际应用中较多。本文通过利用坐标变换的方法,计算了这两种晶体纵向压电性能在空间的分布。通过计算,首先我们发现这两种晶体在空间存在着纵向伸缩压电效应,其次我们还得到了它们在空间的纵向压电系数的最大值和切型。ADP晶体:d33,max=8.66×1012C/N,切型为(xywl)45°/50°;k33,max=0.07,切型为(xywl)45°/55°。KDP晶体:d33,max=4.54×1012C/N,切型为(yzlw)45°/55°;k33,max=0.04,切型为(yzlw)45°/48°。ADP晶体的纵向压电性能略好于KDP。另外,本文还分别对上述计算结果进行了实验验证,实验结果与计算结果基本一致。对两种晶体压电器件的进一步开发和利用具有理论指导意义。 关键词:磷酸二氢钾;磷酸二氢铵;压电效应;机电耦合系数;切型 水热法生长棒状MnOOH和MnO2晶体

张元广1,2,刘奕1,3,郭范1

(1.中国科学技术大学化学系,合肥 230026;2.安庆师范学院化学系,安庆 246011; 3.枣庄学院化学系,枣庄 277100)

摘要:以高锰酸钾(KMnO4)和硫酸铵((NH4)2SO4)为主要原料,在150℃反应16h,水热法生长了棒状MnOOH晶体,然后以合成的棒状MnOOH晶体为前驱物,在硫酸溶液中,130℃水热反应12h,生长了棒状MnO2晶体。探索了KMnO4和(NH4)2SO4的用量以及反应温度对合成棒状MnOOH晶体的影响。利用X射线粉末衍射(XRD)、透射电子显微镜(TEM)和选区电子衍射等(SAED)等手段对产物进行了表征。结果表明,产物MnOOH为单斜结构的纯相,呈现棒状形貌,其平均直径约为72nm, 长度近9.2μm,显示单晶特性;产物MnO2为四方结构的纯相,呈现棒状形貌,其平均直径约为83nm, 长度达11μm,显示单晶特性。 关键词: MnOOH; MnO2; 水热合成; 晶体

Yb0.140Gd0.813La0.047VO4晶体的生长、 光谱和激光损伤阈值

庄乃锋,胡晓琳,赵斌,陈建中,高绍康

(福州大学化学化工学院,福州 350002)

摘要:采用Czochralski方法生长出了Yb0.140Gd0.813La0.047VO4晶体,并测试了Yb3+与La3+在GdVO4晶体中的有效分凝系数。实验结果表明,掺入La3+可在一定程度上提高晶体的激光损伤阈值和晶体生长过程中的稳定性。此外,La3+的引入还有利于减缓高浓度Yb3+掺杂晶体中的荧光捕获效应和浓度猝灭效应的激光损伤阈值。Yb3+在该晶体中具有很宽的吸收半峰宽和荧光半峰宽,分别为26nm和47nm,具有较大的吸收截面和发射截面,分别为2.26×1020cm2和0.96×1020cm2,因此该晶体有望用作可调谐激光晶体和飞秒激光晶体。 关键词:晶体生长;偏振吸收光谱;荧光光谱;激光损伤阈值 CdZnTe探测器晶片的表面处理工艺

张冬敏,朱世富,赵北君,高德友,陈俊,唐世红,方军,程曦

(四川大学材料科学系,成都610064)

摘要:报道了CdZnTe探测器晶片表面钝化工艺对其性能的影响。先采用金相砂纸和化学腐蚀剂对CdZnTe晶片进行机械和化学抛光,然后分别用H2O2溶液和NH4F/H2O2溶液对晶片进行湿法钝化;再用ZC36微电流测试仪和扫描电镜,测试研究了不同钝化时间对CdZnTe晶片电学性质和表面形态的影响。结果发现:用NH4F/H2O2溶液对CdZnTe探测器晶片进行钝化30min,晶片表面形成一层完整的高阻氧化层,表面漏电流最小、晶体电阻率提高1~2个数量级,达到109~10Ω·cm,适合探测器的制备。 关键词:碲锌镉晶片;表面处理;漏电流;电阻率;形貌 [100]金刚石薄膜的辐照响应特性研究

任玲1,王林军1,苏青峰1,刘健敏1,徐闰1,彭鸿雁1,2,史伟民1,夏义本1

(1. 上海大学材料科学与工程学院,上海 200072; 2. 牡丹江师范学院物理系,牡丹江 157011)

摘要:采用热丝辅助化学气相沉积(HFCVD)方法生长得到25μm厚的[100]取向金刚石膜,用以制备辐射探测器。在100 V偏压下,测得暗电流为16.1 nA,55Fe X射线(5.9 keV)和241Am α粒子(5.5 MeV)辐照下的净光电流分别为15.9nA和7.0nA。光电流随时间的变化先快速增加随后由于“pumping”效应逐渐达到稳定。X射线和α粒子辐照下的平均电荷收集效率分别为45%和19%,并由Hecht理论计算得到对应的电荷收集距离为11.25μm和4.75μm。 关键词:金刚石膜,辐射探测器,光电流,电荷收集效率 等径角挤压Al4.25%Cu多晶材料的裂纹产生与扩展

毕见强, 孙康宁,尹衍升, 王素梅, 范润华

(山东大学材料液态结构及其遗传性教育部重点实验室,工程陶瓷山东省重点实验室,济南 250061)

摘要:本文使用内角为90°、外角为30°的模具对2A12铝合金进行了等径角挤压实验,并采用HitachiS800透射电镜(TEM)研究了材料内部裂纹的产生和扩展。结果表明:挤压两次后的试样内部没有产生微裂纹,挤压三次后的试样中观察到了微裂纹的出现,而位错塞积是裂纹产生和扩展的主要因素。所以,2A12铝合金等径角挤压过程中,应该在两次挤压后进行退火处理,保证后续挤压的顺利进行。

关键词:等径角挤压; A14.25%Cu合金; 裂纹;位错

Si基上电沉积Cu薄膜的形貌与择优取向

张雅婷1,徐章程1,李菲晖2

(1.南开大学泰达应用物理学院,弱光非线性光子学材料先进技术及制备教育部重点实验室,天津 300457;

2.天津大学化学化工学院,天津 300072)

摘要:采用电化学沉积技术在Si衬底上沉积了Cu膜。场发射扫描电镜和X射线衍射分析表明:膜中存在Cu纳米颗粒, 并且表现出择优取向,与衬底的取向和斜切角度以及沉积电流密度有关。在Si(100) 衬底上,铜(220)晶面的织构系数随电流密度的增加而增加。在相同沉积条件下,在斜切角较小的Si(111)和Si(100)衬底上择优取向面都是铜 (220) 面,而在斜切角为4°的Si(111)衬底上铜(111)晶面为择优取向面。 关键词:Cu;电沉积; Si衬底;择优取向 Bi2Te3纳米晶溶剂热合成及表征

刘松1,曹传宝1,籍凤秋2,安晓强1,许亚杰1

(1. 北京理工大学材料科学研究中心,北京 100081;2. 石家庄铁道学院交通工程分院, 石家庄 050043)

摘要:采用溶剂热方法,在水合肼溶剂中通过添加适量表面活性剂十二烷基硫酸钠(SDS),在180 ℃下反应10 h后成功地制备了不同形貌的纯相Bi2Te3纳米晶,包括纳米颗粒、纳米棒和花瓣状纳米片。用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能量色散谱仪(EDS)对产物进行了表征,探讨了表面活性剂用量和温度对产物形貌的影响,提出了可能的形成机理。 关键词:Bi2Te3;纳米晶;纳米棒;纳米片;溶剂热合成

水热法合成SnO2 金红相纳米柱和亚微米晶体

张子生, 张晓军,王伟伟,李军, 刘超, 韦志仁

(河北大学物理科学与技术学院,保定 071002)

摘要:本文采用水热法,以SnCl4·5H2O为前驱物,在180℃,填充度为68%,反应时间8h,强酸环境条件下合成了SnO2纳米金红相晶体,直径约为5~10nm,长30~100nm。加入一定量的NaOH,调节溶液pH值为强碱性(pH=11),同样条件下也合成了SnO2金红相纳米柱晶体,长200nm、直径10~20nm。提高水热反应的温度为430℃,矿化剂为3mol/L NaOH,反应时间24h,合成了亚微米金红相SnO2晶体,最大线度为300nm。 关键词:二氧化锡; 水热合成; 纳米柱; 晶体

p型ZnO 的获取以及衬底温度对薄膜特性的影响

范红兵1,2,张晓丹2,赵颖2,孙建2,魏长春2,谷士彬1,张存善1

(1.河北工业大学信息学院,天津 300130;2.南开大学光电子薄膜器件与技术研究所, 南开大学光电子薄膜器件与技术天津市重点实验室,

光电信息技术科学教育部重点实验室(南开大学,天津大学),天津 300071)

摘要:本文主要讨论了采用改进的超声雾化设备制备了不同衬底温度条件下的ZnO 薄膜。研究了该系统下不同衬底温度对ZnO薄膜电学、结构特性的影响。霍耳测试结果表明:获得了p型ZnO薄膜,其载流子浓度高达1.30×1019cm 3 。样品的X射线衍射和场发射扫描电子显微镜的测试结果显示,在该系统下450℃时薄膜结晶性能最佳。 关键词:ZnO;p型传导;超声喷雾热分解;衬底温度

高强、低致密度Ni3Al/HAP生物陶瓷复合材料

的制备与性能研究

孙昌,孙康宁,李爱民, 刘爱红,刘晓飞 (山东大学材料液态结构及其遗传性教育部重点实验室,工程陶瓷山东省重点实验室,济南 250061)

摘要:本文主要对Ni3Al/HAP生物陶瓷复合材料的制备及性能进行了初步研究。采用XRD分析了复合材料的相组成,通过组织学观察考察了复合生物陶瓷的生物相容性。研究结果表明:复合材料具有较好的力学性能和生物相容性。 关键词:羟基磷灰石;Ni3Al/HAP;生物陶瓷;复合材料

单壁碳纳米管储氢中管外H2势能的拟合函数

郭连权1,马贺1,王帅1,韩东1,李辛2

(1.沈阳工业大学理学院,沈阳 110023;2.沈阳药科大学基础学院,沈阳 110015)

摘要:H2分子与管的作用势能曲线是碳纳米管储氢模拟研究中的一项重点内容,建立势能曲线相应的函数表达式更具有理论价值和实际意义。本文从LennardJones势出发,建立了H2分子与C原子之间的作用势能模型,借助于分子动力学(MD)方法,模拟计算了H2分子与管的作用势能曲线。通过对管外H2分子势能曲线的拟合,找到了最佳参数,建立了管外统一形式的势能数学表达式,为碳纳米管的储氢研究提供了相应的理论依据。 关键词:碳纳米管;储氢;势能;拟合函数;计算机模拟 不同工艺制备纳米氧化锆的研究

王焕英1, 国占生1,邢广恩1,宋秀芹2

(1.衡水学院应用化学系,衡水 053000;2.河北师范大学化学学院, 石家庄 050016)

摘要:采用一般化学沉淀法(正向和反向)、均匀沉淀法和水热法来制备纳米氧化锆,研究了制备工艺对ZrO2粒度分布、粒径大小、团聚程度和形貌等的影响,结果表明采用反向沉淀法制备的纳米ZrO2粒子颗粒细小、均匀性好;均匀沉淀法中微波诱导要优于常规加热法,并讨论了添加剂对纳米氧化锆粒子的影响。 关键词:纳米氧化锆; 化学沉淀法; 水热法 孪生对靶直流磁控溅射制备ZnO:Al薄膜

及其特性研究

李微,孙云,何青,刘芳芳,李凤岩

(南开大学光电子薄膜器件与技术研究所,天津 300071;天津市光电子薄膜器件与技术重点实验室,天津 300071)

摘要:本文以ZnO:Al(ZAO)陶瓷为靶材,采用孪生对靶直流磁控溅射工艺在玻璃衬底上制备出高质量的铝掺杂氧化锌透明导电膜,研究了该薄膜的结构、光电及力学特性。采用孪生对靶制备ZAO薄膜可使样品避开等离子体直接轰击,减少基底薄膜的损伤。制备的薄膜具有结晶程度高、电阻率低、迁移率高等优点。ZAO薄膜的最低电阻率达到了4.47×104Ω·cm,在可见光区的平均透过率达到85%以上,非常适合做为铜铟硒(CIS)薄膜太阳电池窗口层。 关键词:孪生对靶;磁控溅射;ZnO:Al

非极性GaN薄膜及其衬底材料

周健华1,2,周圣明1,邹军1,2,黄涛华1,2,徐军1,谢自力3,韩平3,张荣3

(1.中国科学院上海光学精密机械研究所,上海 201800;2.中国科学院研究生院,北京 100039; 3.南京大学物理系,南京 210093)

摘要:本文分析了在不同衬底上生长无极性GaN薄膜的情况,这些衬底主要包括γLiAlO2、r面蓝宝石等。通常在蓝宝石上制备的GaN外延膜是沿c轴生长的,而c轴是GaN的极性轴,导致GaN基器件有源层量子阱中出现很强的内建电场,发光效率会因此降低,发展非极性面外延,有望克服这一物理现象,使发光效率提高。 关键词:r面蓝宝石; γLiAlO2;a面GaN;m面GaN

低温AlN插入层降低硅基GaN膜微裂

冯玉春,刘晓峰,王文欣,彭冬生,郭宝平 (深圳大学光电子学研究所,广东省光电子器件与系统重点实验室,光电子器件与系统教育部重点实验室,深圳 518060)

摘要:为了降低MOCVD外延硅基GaN膜层中的应力、减少硅基厚GaN层的微裂;在高温GaN层中插入低温AlN。低温AlN插入层可平衡HTGaN生长和降温过程引起的张应力,降低厚膜外延层的微裂,已研制出厚度超过1.8微米无微裂GaN外延层。本文重点研究了低温AlN生长温度对HTGaN材料的影响,给出了较佳的LTAlN生长温度。采用扫描电子显微镜(SEM),原子力显微镜(AFM)和高分辨率双晶X射线衍射(DCXRD),对样品进行了测试分析。试验和测试结果表明低温AlN的生长温度至关重要,生长温度过低影响GaN晶体质量,甚至不能形成晶体;生长温度过高同样会影响GaN结晶质量,同时降低插入层的应力平衡作用;实验结果表明最佳的LTAlN插入层的生长温度为680℃左右。 关键词:Si(111);GaN;AlN

用热CVD法制备片状碳纳米材料的研究

李明华,张海燕,魏爱香,陈易明,王力,朱清锋

(广东工业大学材料与能源学院, 广州 510006)

摘要:采用阳极氧化法在草酸溶液中制备了孔径约为100nm的多孔氧化铝(AAO)模板。利用此模板在不负载任何催化剂的条件下,利用热CVD装置制备出片状碳纳米薄膜,并对此片状薄膜做了SEM,TEM显微观察和EDS能谱分析,对其形成条件和生长机理等方面做了探讨分析,为在氧化铝模板上生长包括管状、片状、棒状等形状的碳纳米材料提供了一定的借鉴意义。 关键词:多孔氧化铝模板;热化学气相沉积;片状碳纳米材料 不同耦合间隙对大直径SiC晶体生长感应

加热系统的影响

张群社, 陈治明, 李留臣,蒲红斌, 封先锋, 陈曦

(西安理工大学自动化与信息工程学院,西安 710048)

摘要:本文采用有限元分析方法系统地研究了大尺寸SiC晶体PVT法生长装置中的加热组件不同的耦合间隙对生长系统中的感应磁场、感生电流和焦耳热的影响;分析比较了取不同的耦合间隙时系统达到热平衡状态所需时间的不同。得出了在中频电源的输出功率和频率都不变的前提下,在线圈匝数已固定的条件下,通过缩小耦合间隙可以提高系统的加热效率,缩短系统达到热平衡状态所需时间的结论。 关键词:SiC;PVT法;磁矢势;焦耳热

中红外非线性光学晶体的研究进展

董春明,王善朋,陶绪堂 (山东大学晶体材料国家重点实验室,济南 250100)

摘要:本文综述了几种重要的中红外非线性光学晶体的研究进展,分别详细介绍了各自的结构特点、非线性性能以及他们在频率变换方面的重要应用。提出了在中红外非线性光学晶体生长中遇到的困难,并探讨了解决问题的途径。认为生长性能优异、足够尺寸的红外非线性光学晶体具有非常重要的应用价值,并对中红外非线性光学晶体的研究进行了展望。 关键词:中红外;频率变换;非线性光学晶体 锰锌铁氧体纳米粉体的烧结过程及其性能测试分析

崔银芳,王 新,姜延飞,李养贤 (河北工业大学材料学院, 天津 300130)

摘要:本文研究了锰锌铁氧体纳米粉体的烧结过程及晶粒生长规律,采用传统成型工艺和分段烧结方式,研究坯体的致密化和晶粒生长情况。烧结体的密度、微观结构和相组成分别采用阿基米德法、扫描电镜(SEM)和X射线衍射仪(XRD)进行测试分析。烧结体的磁性能用振动样品磁强计(VSM)来测定。另外,根据[311]衍射峰的半高宽,利用Scherrer公式计算烧结体晶粒的大小。结果表明,在900℃烧结时,烧结体的密度达到了功率锰锌铁氧体材料所需的最佳密度,此时晶粒生长较好,得出900℃为MnZn铁氧体纳米粉体的最佳烧结温度,此时烧结体的密度为4.8245g/cm3。 关键词:MnZn铁氧体纳米粉体;烧结;烧结体密度;晶粒生长 Sr2+对GdVO4晶体生长和拉曼性能的影响

钟富兰, 朱进, 陈建中, 庄乃锋

(福州大学化学化工学院, 福州 350002)

摘要:本文报道了Sr2+离子掺杂对GdVO4晶体生长和拉曼性能的影响。SrxGd1xVO4晶体粉末经X射线粉末衍射分析,其结果仍属四方晶系,具有锆英石结构。实验表明,高掺杂浓度时,Sr2+离子不易取代Gd3+离子进入GdVO4晶体的晶格,易导致SrxGd1xVO4晶体开裂和产生包裹体。XPS实验证明,SrxGd1xVO4晶体中钒元素为+5价。同时测试了常温下SrxGd1xVO4晶体的拉曼光谱,发现随着Sr2+离子浓度增加,在884cm1处的VO4反对称伸缩振动逐渐增强,表明Sr2+离子的掺入影响了GdVO4晶体的拉曼性能。 关键词:SrxGd1xVO4晶体;晶体生长;拉曼光谱

掺Nd钒酸盐晶体热导率的拉曼光谱研究

赵朋,张海昆鸟, 苏燕,周城,任妙娟,张仲

(济南大学理学院物理系,济南 250022)

摘要:运用晶格动力学观点推导了热导率与积分拉曼散射强度的关系,测量了Nd:YVO4 (简称NYV)和Nd:GdVO4 (简称NGV)不同配置下的高温拉曼光谱和其a、c向的热导率,理论与实验非常吻合。 关键词:拉曼光谱;钒酸盐晶体;热导率

水热均匀沉淀法制备Zr(OH)x/NH4Cl

复合结构枝蔓晶

孙笑非,宋秀芹 (河北师范大学化学与材料科学学院,石家庄 050016)

摘要:本文以ZrOCl2·8H2O和CO(NH2)2为原料,采用水热均匀沉淀法,制备出了一种新型Zr(OH)x/NH4Cl复合结构对枝蔓晶,并用XRD、SEM、TEM、EDS对产品进行表征。对枝蔓晶的结构和形成进行了分析认为NH4Cl通过氢键作用对Zr(OH)x 形成不完全包覆,并通过晶体生长方式形成枝蔓晶。 关键词:氧化锆;枝蔓晶;水热法;均匀沉淀法 熔盐法合成片状SrBi4Ti4O15粉体

张柯,黄金亮,李丽华

(河南科技大学材料科学与工程学院,洛阳 471003)

摘要:采用NaClKCl熔盐法合成了生长各向异性的片状SrBi4Ti4O15粉体,用XRD分析了粉体相的结构,用SEM观察了粉体的微观形貌,讨论了不同预烧温度对合成物结构和微观形貌的影响。与固相法相比,熔盐法合成的粉体具有(00l)择优生长的优点。在850~1050℃之间,合成粉体的片状结构趋于明显,粉体生长各向异性随温度的升高呈现出先增加后减小的趋势,各向异性明显的SrBi4Ti4O15粉体的最佳合成温度为900~1000℃。 关键词:熔盐法; SrBi4Ti4O15; 择优生长; 片状结构

Cr:KNSBN晶体两波耦合及其图像存储

郭庆林,魏丽静,苏红新,郭建新,张金平,怀素芳,傅广生

(河北大学物理科学与技术学院,保定 071002)

摘要:本文以HeNe 632.8nm激光为写入光,在非同时读出条件下,实验研究了e偏振光写入Cr:KNSBN晶体两波耦合过程中信号光和泵浦光的透射光强随时间的变化,以及单束泵浦光的透射光强随时间的变化,实验结果表明,泵浦光损失的能量几乎全部转移到了信号光方向,基本不存在散射光;并以二值化图像作为物在晶体内进行了图像存储实验,其再现图像清晰,信噪比高,没有观察到扇形光的影响。 关键词:Cr:KNSBN晶体;两波耦合;光扇效应;图像存储

柠檬酸盐法制备超细Zn(Al)O的微波介电性能研究

曾国勋, 张海燕, 胡礼初,王力, 陈易明 (广东工业大学材料与能源学院,广州 510640)

摘要:本文研究了利用柠檬酸盐法制备的Zn(Al)O的介电性能。XRD分析显示先驱体燃烧后制成了单相的Zn(Al)O。热重分析显示先驱体易发生不完全燃烧,产生炭黑残留。燃烧产物经600℃,90min加热除去炭黑。2~18GHz的介电谱测量结果显示含炭黑的Zn(Al)O的复介电常数无论实部还是虚部均高于不含炭黑Zn(Al)O;介电谱还显示Zn(Al)O分别在X、Ku波段存在两个损耗峰。其中X波段的损耗峰位易受炭黑的影响,发生移动;Ku波段的损耗峰较稳定。文章理论计算Zn(Al)O微波吸收率。显示出Zn(Al)O对微波具有良好的透波作用。因此,当Zn(Al)O做红外反射材料时,不影响底层材料对微波的吸收。 关键词:Zn(Al)O;微波;介电性能

纳米薄膜材料的蓝光发射特性及其研究进展

彭英才1,2,傅广生3,王英龙3

(1.河北大学电子信息工程学院,保定 071002;2.中国科学院半导体研究所半导体材料科学重点实验室,北京 100083;

3.河北大学物理科学与技术学院,保定 071002)

摘要:蓝光发射是纳米半导体材料发光特性的一个重要研究方向。本文首先简要介绍了蓝光发射的物理机制,接着重点评述了几种主要纳米薄膜材料,如ZnO、GaN、CdS和Si纳米结构等,近3~5年内在蓝发光射特性方面所取得的最新研究进展。最后,对存在问题和发展前景进行了讨论与展望。 关键词:纳米薄膜材料;蓝色发光;器件应用

染料吸附对氯化银微晶表面结构的影响

李晓苇, 李莉,张荣香,张继县,江晓利,杨少鹏 (河北大学物理科学与技术学院,保定 071002)

摘要:利用微波吸收相敏检测技术测量了纯氯化银微晶的光电子衰减曲线,再结合光电子衰减动力学方程,确定了微晶表面和内部的电子陷阱参数,并以此为基础分析了染料的吸附对微晶表面结构的影响。发现吸附不仅会在微晶表面产生填隙银离子同时会对表面陷阱产生修饰作用,且随着染料吸附量的减少,产生银离子的作用退化并最终消失,而修饰作用凸现并逐渐增强,直至填隙银离子不再产生,修饰作用也达到了最大,随后修饰作用将随染料吸附量的继续减少而变弱。 关键词:电子陷阱; 染料吸附; 卤化银微晶; 表面结构; 表面修饰

Al2O3/TiB2/AlN/TiN复合陶瓷材料的 力学性能及显微结构

刘长霞1,张建华1, 孙军龙1, 张希华2

(1.山东大学机械工程学院,济南 250061;2.山东大学材料科学与工程学院,济南 250061)

摘要:将金属Al、Al3Ti和TiB2以AlTiB中间合金的形式引入Al2O3基体材料中,采用热压原位反应生成法制备了Al2O3/TiB2/AlN/TiN复合陶瓷材料。复合材料在烧结过程处于过渡液相烧结,并有新相AlN和TiN生成;对热压烧结后材料的硬度、断裂韧性和抗弯强度进行了测试和分析;分析了复合材料力学性能随AlTiB体积百分含量的变化规律;探讨了复合材料断面断裂方式的变化对其力学性能的影响;并对AlTiB中间合金的细化特性进行了分析。 关键词:氧化铝;AlTiB中间合金;复合陶瓷;细化特性 PZT基反铁电材料研究进展

夏志国,李强

(清华大学化学系,北京 100084)

摘要:在综述Pb(Zr,Ti)O3(PZT)基反铁电材料的研制与性能研究进展的基础上,重点探讨了PZT95/5反铁电材料和在PZT基础上掺杂改性的Pb(Zr,Sn,Ti)O3(PZST),(Pb,La)(Zr,Sn,Ti)O3 (PLZST)反铁电材料。总结了利用La3+、Nb4+、Hf4+、Sr2+、Ba2+和Nd3+等离子对富锆PZT以及PZST粉体、陶瓷以及薄膜材料的掺杂取代改性研究。讨论了各类PZT基反铁电材料的铁电(FE)反铁电(AFE)相变机理以及其场致应变性能。展望了PZT基反铁电材料今后研究与应用的发展方向。 关键词:反铁电材料;铁电反铁电相变;PZT95/5;PZST;PLZST

四方相区NBTKBT无铅铁电介电弛豫

与铁电相变研究

李月明1,陈文2,徐庆2,江向平1,张玉平1

(1. 景德镇陶瓷学院,景德镇 333001;2. 武汉理工大学材料科学与工程学院,武汉 430070)

摘要:本文研究了具有四方结构的(Na1xKx)0.5Bi0.5TiO3体系中x=0.22,0.26和0.30陶瓷材料不同温度下的电滞回线,结合变温XRD和介电温谱分析,发现该体系四方结构的组成为反铁电体,但紧靠准同型相界的四方结构由于场诱导下引起的反铁电铁电相变,表现出铁电体特性,材料在升温过程中由于反铁电宏畴向微畴的转变导致了介电峰的产生,且在介电温谱上表现出强烈的介电常数频率依赖性,为弛豫铁电体特征。 关键词:钛酸铋钠;钛酸铋钾;反铁电相变;介电弛豫

Co2+:BeAl2O4晶体的提拉法生长及光谱特性

夏海平,张新民,张约品,章践立,王金浩 (宁波大学光电子功能材料重点实验室,宁波 315211)

摘要:应用提拉法,采用合适的化学组分配比和化料过程、以及选用适宜的固液界面温度梯度与生长速度等优化工艺条件,成功地生长出了初始Co2+离子掺杂浓度为0.15mol%、尺寸48×85mm2的优质Co2+:BeAl2O4晶体。测定了晶体的吸收光谱,观测到496与 640nm二个主要吸收带,它们分别归属于八面体配位中Co2+的T1(4F)→4T1(4P)跃迁与四面体配位中Co2+的A2(4F)→4T1(4P)跃迁。从晶体的吸收光谱与呈现的粉红色颜色特征可推断大多数的Co2+离子取代BeAl2O4晶体中的Al3+,形成Co2+离子的八面体格位。研究了不同光波长激发下,晶体在可见光波段的荧光特征,观测到678nm波段的荧光发射,这归属于四面体格位中Co2+的电子从4T1(4P)到4A2(4F) 能级的跃迁。 关键词:铝酸铍晶体;提拉法;Co2+离子;光谱 KDP晶体的点状籽晶法生长及其缺陷研究

李晓兵,滕冰,钟德高,鲁晓东,庄严

(青岛大学物理系,青岛 266071)

摘要:研究了溶液pH值对KDP晶体生长形态的影响,进行了晶体生长实验和参数对比。以提高溶液pH值为主要手段在低过饱和度下进行KDP晶体点状生长。对点状法生长的晶体进行了缺陷分析,测定了晶体不同区域的金属离子含量并进行了对比分析。实验表明溶液pH值对晶体各向的相对生长速度有显著的影响。在pH=5.0、低过饱和度(σ<0.02)条件下生长出50×50×50mm3的晶体。 关键词:KDP晶体;点状籽晶;pH值;缺陷;阳离子含量

双周期厚度调制的多量子阱的透射谱

王同标, 刘晓亮, 尹承平, 刘念华 (南昌大学物理系,南昌 330047)

摘要:采用传输矩阵方法,研究了一维双周期厚度调制的多量子阱的透射谱。当量子阱的宽度被周期性地调制时,在原来的单一周期势的禁带中出现了一些窄带,落在这些窄带内的电子具有较强的局域性。 关键词:双周期;量子阱; 局域化

电沉积法制备CdS薄膜及其性能研究

葛艳辉,史伟民, 魏光普, 徐菁, 邱永华

(上海大学电子信息材料系, 上海200072)

摘要:采用电沉积法制备了CdS薄膜。分别用XRD及SEM分析了薄膜的结构和表面形貌。研究了不同温度和不同沉积电压对薄膜表面硫与镉的化学成分比的影响。最佳的沉积电压为2.5~3V之间。制作了ITO/nCdS/pSnS/Ag结构的太阳能电池,在100mW/cm2的光强下其开路电压0.2V,短路电流13.2mA/cm2,填充因子0.31,转换效率0.81%。 关键词:CdS; 电沉积; 太阳能电池

微波法合成新型红色长余辉材料Gd2O2S:

Eu,Mg,Ti中助熔剂的影响

翟永清,刘元红 (河北大学化学与环境科学学院,保定 071002)

摘要:用微波辐射法首次合成了红色长余辉材料Gd2O2S:Eu,Mg,Ti,用X射线粉末衍射(XRD)、扫描电镜(SEM)、荧光分光光度计等手段对合成产物进行了分析和表征,并研究了不同助熔剂Li2CO3,Na2CO3,K2CO3,Na3PO4,KH2PO4以及Li2CO3和Na2CO3共同作用对材料的微观形貌及发光性能的影响。结果表明:不同的助熔剂的加入均可得到单相晶体,材料的晶体结构为六方晶系,与Gd2O2S的相同。颗粒分散性较好,晶粒尺寸以及形貌因助熔剂的不同而有所差别。发光性质研究表明:不同助熔剂的加入并没有改变样品发射谱主峰位置(627nm),但对其峰强度产生明显影响,激发光谱中的情况与此相似。研究发现Li2CO3和Na2CO3共同作用可有效延长余辉时间。 关键词:助熔剂; Gd2O2S:Eu,Mg,Ti; 微波法; 光谱; 长余辉 微管ZnO可控生长的研究

杨丽萍, 李燕 ,邓宏

(电子科技大学微电子与固体电子学院 ,成都 610054)

摘要:本文采用水热法在玻璃基片上生长出了微米级六棱管状ZnO。采用X射线衍射(XRD)、扫描电子显微镜(SEM)对所制备的样品进行物相结构及表面形貌的分析。结果显示所制备的样品为六角晶系纤锌矿结构的ZnO。通过在基片上预先生长不同尺度中空ZnO球的方法能够成功的生长出不同尺寸微米管状ZnO,初步实现了水热合成微米管状ZnO的可控生长。 关键词:ZnO;微米管;可控生长 硅纳米管的稳定性及性能的理论研究

李小祥, 唐元洪,裴立宅 (湖南大学材料科学与工程学院,长沙 410082)

摘要:硅纳米管(SiNTs)是一种继碳纳米管(CNT)和硅纳米线(SiNWs)之后的全新一维纳米材料。文中介绍了硅纳米管理论研究的最新进展,主要从理论上对硅纳米管的稳定性、稳定存在的形式及其性能,包括导电性能、热稳定性能、机械性能等进行了综述,最后,探讨了硅纳米管的发展前景并提出展望。 关键词:硅纳米管;稳定性;性能

NiZrO2纳米复合电铸层的制备及纳米颗粒 分布均匀性研究

张文峰1,2, 朱荻1

(1,苏州职业大学机电系,苏州215011; 2,南京航空航天大学机电学院,南京 210016)

摘要:研究了在复合电铸过程中,当其它工艺参数一定时,复合电铸层的沉积速率及其厚度随时间的变化趋势, 以及复合电铸层表面微观形貌随电沉积时间的变化趋势。测定了复合电铸层的组织成分,并就纳米颗粒在复合电铸层表面和横截面上分布的均匀性进行了评价。结果表明,复合电铸层表面平整,组织均匀致密,其组成主要是镍和所复合的纳米颗粒,纳米颗粒较为均匀地分散在复合电铸层中。 关键词:复合电铸;纳米颗粒;表面形貌;组织成分;分布均匀性 草酸二甲酯均相沉淀法制备超细CeO2的研究

梅燕韩业斌聂祚仁

(北京工业大学材料科学与工程学院,北京 100022)

摘要:以Ce(NO3)3·6H2O和草酸二甲酯(DMO)为原料,采用均相沉淀法制备超细CeO2粉体。借助TEM、SEM、 XRD及DTATG等测试手段,观察分析并研究了初生、反应30min及反应2h的CeO2前驱体,干燥并500℃焙烧得到的最终产物——超细CeO2粉体的制备过程。结果表明:CeO2前驱体Ce2(C2O4)3·10H2O的形成与最终产物CeO2在形状上相似,说明形貌有一定的遗传继承性,故可通过控制反应条件来控制前驱体的形貌及大小,达到控制最终产物的目的。制备了块状的、分散均匀良好的,粒径大小约为1μm的超细CeO2粉体。 关键词:草酸二甲酯;均相沉淀法;超细;二氧化铈 掺钕KGW激光晶体的各向异性吸收光谱 及其上转换发光

刘璟1,郑志强1,黄抒洁1,李小燕1,冯卓宏1,洪锦棉1

林琳1,明海2

(1.福建师范大学物理与光电信息科技学院,福州 350007; 2. 中国科学技术大学物理系,合肥 230026 )

摘要:在室温下测量了掺钕钨酸钾钆(Nd3+∶KGW)晶体三个晶轴方向的吸收光谱,其吸收谱带强度明显显示各向异性。将JuddOfelt(JO)理论进行修正,使其扩展应用于处理各晶轴方向的吸收光谱,计算出三个晶轴方向的各光谱带吸收系数、电偶极跃迁振子强度,其结果说明了Nd3+:KGW吸收光谱存在着各向异性。同时还研究了该材料在812nm激发下的上转换荧光特性,观察到较强的蓝色荧光。

关键词:Nd3+∶KGW;吸收光谱; 各向异性; 上转换发光 炼丹术和气相晶体生长

蒋宛莉1,2,张熙惟2

(1.山东大学晶体材料国家重点实验室,济南 250100;2.山东大学历史文化学院, 济南 250100)

摘要:本文简要论述了炼丹术的兴起、发展、衰落,并试图从晶体学的角度阐述中国古代炼丹术对本草学、矿物学、近代化学及气相晶体生长的贡献。通过对古人相当分散记载的历史文献的搜集、整理,展示我国古代的气相晶体生长的概貌,论述了炼丹术和气相晶体生长的关系,探讨了炼丹术衰落的原因,最终得出气相晶体生长起源于中国古代的炼丹术,银珠(灵砂)是最早采用气相法生长的人工晶体这一结论。 关键词:炼丹术;气相生长;人工晶体

Growth of La2CaB10O19 Single Crystals by Seedsubmerged Growth Technique

JING Fangli1,2,WU Yicheng1,FU Peizhen1,ZU Yanlei1,2

(1.Beijing Center for Crystal Research and Development,Technical Institute of Physics and Chemistry,

Chinese Academy of Sciences,Beijing 100080,China; 2.Graduate School of the Chinese Academy of Sciences,Beijing 100039,China)

(Received 14 February 2006)

Abstract:La2CaB10O19 single crystals were grown from CaOLi2OB2O3 flux by seedsubmerged technique.The crystal exhibit platelike growth habit and it is likely to cleave along (001) faces due to the structure of crystal.The direction of seed crystals has great influence on crystal growth.It is found that the [101] direction benefit to crystal growth than other directions.

Key words:La2CaB10O19 crystal;flux;cleavage

Determination of Composition and Observation of Defects of

Nearstoichiometric Lithium Niobate Crystal

HUANG Qingjie1, WANG Jiyang2

(1. School of Information Science and Engineering,Shandong University, Jinan 250100,China;

2. State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100,China)

(Received 4 April 2006)

Abstract:Nearstoichiometric LiNbO3 crystal was grown from a melt with addition of K2O by using Czochralski method. Different methods were used to determine the crystal composition. These measurements indicate that there is 49.8mol% Li2O content in the crystal. Investigation of crystal defects reveals the crystal quality could be improved. The reason of inclusion that exists in the crystal is explained.

Key words:LiNbO3; nearstoichiometric; defects; determination of composition; chemical etching

Synthesis of Nanocrystalline GaN by the Solgel Method

QIU Hailin, WANG Yinchun,XU Guangyan,CAO Chuanbao

(Research Center of Material Science, Beijing Insititute of Technology, Beijing 100081, China) (Received 4 January 2006)

Abstract:Singlephase wurtzite GaN nanocrystals with an average diameter of 11.2 nm were synthesized through a solgel technique and subsequent nitrition. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) confirmed they had a hexagonal structure and a narrow size distribution of the nanocrystals. Xray powder diffraction (XRD) and highresolution transmission electron microscopy (HRTEM) measurement showed that the GaN powder was of singlephase wurtzite structure with a considerable fraction of structural defects such as twin and stacking faults. The IR spectrum showed that only the GaN stretch is present at 580cm-1. Roomtemperature photoluminescence measurement reveals a broad emission ranging from 2.6 to 3.2 eV with some fine structures, which are believed to be associated with the defect levels.

Key words:GaN; solgel; photoluminescence

Preparation of Anhydrous Lanthanum Chloride

for LaCl3:Ce3+ Crystal Growth

CHEN Hongbing1, ZHOU Changyong1, YANG Peizhi2,JIANG Chengyong1, PAN Jianguo1

(1. State Key Base of Novel Functional Materials and Its Preparation Science, Institute of Solid State Materials

Chemistry, Ningbo University, Ningbo 315211,China;

2. Kunming Institute of Physics, Kunming 650223,China)

(Received 18 November 2005)

Abstract:The preparation of anhydrous lanthanum chloride for LaCl3:Ce3+ crystal growth by chlorinating sintering dehydration process is reported in this paper. The dehydration procedure of LaCl3·7H2O was investigated by DTA/TG analysis in order to explore an effective way to avoid the hydrolysis reaction. Using LaCl3·7H2O as the starting materials, anhydrous lanthanum chloride was prepared by the dehydration treatment in HCl atmosphere. The optimum conditions for the chlorinating sintering dehydration process had been obtained by a series of experiments. To confirm the purity of the anhydrous lanthanum chloride obtained, it had been used to grow LaCl3:Ce3+ single crystals. In the chlorinating sintering dehydration process, the anhydrous lanthanum chloride with high purity can be prepared by means of sintering LaCl3·7H2O at 220230℃ for 67h in dried HCl atmosphere. The anhydrous lanthanum chloride is applied to grow colorless transparent LaCl3:Ce3+ single crystals successfully.

Key words:anhydrous lanthanum chloride; sintering; dehydration; crystal growth

Annealing Effect on the Absorption Spectra of Nd,Cr:GSGG Laser Crystal

SUN Dunlu, ZHANG Qingli, JIANG Haihe, YIN Shaotang

(Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China)

(Received 7 February 2006)

Abstract:By using optical absorption method, we studied the absorption spectra change of Nd,Cr:GSGG crystal grown by CZ method and annealed in different atmospheres. The results indicated that after the Nd,Cr:GSGG crystal was annealed in the oxidation atmosphere, the absorption spectrum exist two absorption bands near 1μm due to some Cr4+ ions in the crystal, which are called 1μm absorption loss. After the Nd,Cr:GSGG crystal was annealed in reducing atmosphere, the absorption bands near 1μm almost disappear fully, which is very helpful to improve the laser efficiency. In addition, the absorption band intensity near 642nm became weak. These data will provide an important reference for the improvement of crystal subsequent treatment processing and the laser design.

Key words:Nd,Cr:GSGG; reducing atmosphere; annealing; absorption loss

Numerical Simulation of the Natural Convection

Influence on Silicon Single Crystal by Cz

YU Huiping1, SUI Yunkang1, WANG Jing2,AN Guoping1

(1.College of Mechanical Engineering and Applying Electronic Technique, Beijing University of Technology, Beijing100022, China;

2.General Research Institute for Nonferrous Metals, Beijing 100088, China)

(Received 19 January 2006)

Abstract:Natural convective has significant effects on the crystalmelt interface shape, temperature distribution and the stress field in Czochralski (CZ) crystal growth. In this paper, twodimensional numerical simulations were carried out to clarify the effect of buoyancy force on melt motion in a CZ crystal system. At low Reynolds numbers, a laminar model was used, while at large Reynolds numbers, a turbulence model was employed. The present paper investigates the natural convection from a low Grashof number 3×106 to a large Grashof number 3×1010,which corresponding to smallsize CZ system to largesize CZ system. The numerical results show that the flow state is not only related to Grashof number but also the ratio of the melt height to the crucible radius. When Gr is large than a critical value 108, the flow becomes unstable, the laminar model is no longer suitable, and it is found that with the increase of Grashof number, the turbulence flow and intensity becomes stronger and temperature gradient near the interface becomes sharper, which is harmful to the crystal growth.

Key words:Czochralski silicon;natural convective;numerical simulation

Calculations and Experimental Measurements of Piezoelectric

Coefficient d33 in ADP and KDP Single Crystals

WANG Yue1, CHANG Xinan2, LIU Guoqing1, JIANG Yijian3

(1.College of Applied Science, Beijing University of Technology, Beijing 100022, China;2.College of Material Science, Beijing University of

Technology, Beijing 100022,China;3.National Center of Laser Technology, Beijing University of Technology, Beijing 100022, China) (Received 8 May 2006,accepted 28 May 2006)

Abstract:ADP (ammonium dihydrogen phosphate) and KDP (patassium dihydrogen phosphate) are classified as 42m point group which both are the famous piezoelectric crystals in earlier last century. But they all have thickness shear piezoelectric effect and no longitudinal piezoelectric properties in principle axis coordinate which has more applications in industry. In this paper, the crystal orientation dependence of longitudinal piezoelectric properties (d33,k33) in these two crystals have been calculated by means of the coordinate transformation method. According to the calculation, it is found that there is longitudinal length extension piezoelectric effect in threedimension space. The maximum values of longitudinal length extension piezoelectric constants (d33,k33) and cuttingtypes are also obtained. For ADP: d33,max=8.66×10-12C/N, cuttingtype (xywl)45°/55°; k33,max=0.07, cuttingtype (xywl)45°/50°. For KDP: d33,max=4.54×10-12C/N, cuttingtype (yzlw)45°/55°; k33,max=0.04, cuttingtype (yzlw)45°/48°. The longitudinal piezoelectric properties of ADP is much better than that of KDP. These above results of d33 are verified by the experimental measurements respectively. These results will be useful for the design of their piezoelectric devices and futher applications.

Key words:patassium dihydrogen phosphate; ammonium dihydrogen phosphate; piezoelectric constants; electromechanical coupling factor; cuttingtypeHydrothermal Growth of Rodlike MnOOH and MnO2 SingleCrystals

ZHANG Yuanguang1,2 ,LIU Yi1,3, GUO Fan1

(1. Department of Chemistry, University of Science and Technology of China, Hefei 230026,China;

2. Department of Chemistry, Anqing Teachers College, Anqing 246011,China;

3. Department of Chemistry, Zaozhuang University, Zaozhuang 277100,China)

(Received 23 January 2006,accepted 14 April 2006)

Abstract:MnOOH singlecrystal rods were synthesized by hydrothermal method at 150℃ for 16h, using KMnO4 and (NH4)2SO4 as main raw materials, and the rodlike MnO2 crystals were prepared at 130℃ for 12h by a hydrothermal process, using the asprepared MnOOH crystals as a precursor. The effects of amount of reactants and reaction temperature on the products were investigated. The asprepared samples were characterized by Xray powder diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction pattern (SAED). The effects of both molar ratios between reactants and reaction temperature on the products were investigated. The results showed that the asprepared MnOOH is a monoclinic single phase, displaying rodlike morphology, its average diameters are 72 nm , length up to 9.2 μm, and exhibiting single crystalline nature. The asprepared MnO2 is a tetragonal single phase, displaying rodlike morphology, its average diameters are 83 nm , length up to 11 μm, and exhibiting single crystalline nature.

Key words:MnOOH; MnO2; hydrothermal synthesis; crystal

Crystal Growth,Spectral Properties and Laser Damage Threshold

of Yb0.140Gd0.813La0.047VO4 Crystal

ZHUANG Naifeng, HU Xiaolin, ZHAO Bin, CHEN Jianzhong,GAO Shaokang

(College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350002, China)

(Received 27 December 2005,accepted 24 February 2006)

Abstract:Yb0.140Gd0.813La0.047VO4 crystal was grown by the Czochralski method. The effective segregation coefficients of the Yb3+ and La3+ ions in crystal are 0.80 and 0.47, respectively. The doping ion of La3+ can improve the laser damage threshold and the crystalgrowth stability of Yb:GdVO4 crystal, weaken the fluorescence quenching and the fluorescence trapping effects of high Yb3+doped crystals. The crystal has large the full widths at half maximum (FWHM) of the absorption and fluorescence spectra, which is 26nm and 47nm, respectively, and the large absorption cross section and emission cross section that is 2.26×1020cm2 and 0.96×1020cm2, respectively. So Yb0.140Gd0.813La0.047VO4 crystal may be applicable for femtosecond laser and for the tunable laser.

Key words:crystal growth; polarization absorption spectrum; fluorescence spectrum; laser damage threshold

Surface Passivation Process of the Wafers for CdZnTe Detector

ZHANG Dongmin, ZHU Shifu, ZHAO Beijun, GAO Deyou, CHEN Jun, TANG Shihong, FANG Jun, Cheng Xi

(Department of Materials Science, Sichuan University, Chengdu 610064, China)

(Received 21 January 2006)

Abstract:The influences of surface passivation process on the properties of the wafers for CdZnTe(CZT) detector were reported. Firstly, the CZT wafers were polished mechanically and chemically by means of metallographic abrasive papers and chemical etchant. Then the wafers were passivated respectively by H2O2 solution and NH4F/H2O2 solution. By using microcurrent test instrument and scanning electron microscopy (SEM), the influences of different passivation time on the electronic properties of the wafers were studied. It was found that when CZT wafers were passivated 30 minutes with NH4F/H2O2 solution, there formed a high resistivity layer of oxide on the surface. The leakage current of the surface is the lowest, resistivity of the crystal heightened for 12 order of magnitude, up to 10910Ω·cm. The wafers can be used for the preparation of CZT detectors.

Key words:CdZnTe wafer; surface treatment; leakage current; resistivity; morphology

Studiy on Irradiation Response of [100]oriented Diamond Film

REN Ling1, WANG Linjun1, SU Qingfeng1, LIU Jianmin1, XU Run1, PENG Hongyan1,2, SHI Weimin1, XIA Yiben1

(1.School of Materials Science and Engineering, Shanghai University , Shanghai 200072 ,China;

2.Physics Department, Mudanjiang Normal College, Mudanjiang 157011, China)

(Received 10 January 2006,accepted 10 April 2006)

Abstract:A radiation detector was fabricated by [100]oriented diamond film which was deposited by hot filament chemical vapor deposition (HFCVD) method. The thickness of the film was 25μm. Under a bias voltage of 100V, the dark current was 16.1nA . The net photocurrent was also obtained as 15.9 nA and 7.0 nA under the irradiation of 55Fe(5.9 keV) X ray and 241Am (5.5 MeV) α particles, respectively. The photocurrent increased rapidly at first and reached stably for the “pumping” effect with the time elapsing. The charge collection efficiency was 45% (Xrays) and 19% (α particles), corresponding to the charge collection distance of 11.25 μm and 4.75 μm by calculating according to Hecht theory.

Key words:oriented diamond film; radiation detector; photocurrent; charge collection efficiency

Formation and Growth of Cracks of A14.25%Cu Alloy Pressed by ECAP

BI Jianqiang, SUN Kangning, YIN Yansheng, WANG Sumei, FAN Runhua

(Key Laboratory of Material Liquid Structure and Heredity,of Ministry Shandong University Key Laboratory of Engineering Ceramics of

Shandong Province, Jinan 250061, China )

(Received 9 January 2006)

Abstract:A14.25%Cu alloy was suffered from equal channel angular pressing(ECAP) in this experiment, in which an ECAP die with the inner angle =90°, outer angle ψ=30°. It was studied that the cause and growth of cracks of ECAPed A14.25%Cu alloy by TEM method. It shows that no cracks are found in samples after two passes ECAP, but they are observed in samples after three passes. And dislocation movement is the main cause of cracks growth. For ECAP samples should be annealed after two passes.

Key words:equal channel angular pressing (ECAP); A14.25%Cu alloy; crack; dislocation

Morphology and Preferential Orientation of Electrodeposited Cu/Si Thin Films

ZHANG Yating1, XU Zhangcheng1,LI Feihui2

(1. Key Laboratory of Advanced Technique and Fabrication for WeakLight Nonlinear Photonics Matetrials ,Minstry of Education,

Nankai University, Tianjin 300457, China;

2. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China)

(Received 6 February 2006)

Abstract:The morphology and preferred orientation of electrodeposited copper films on silicon substrates were studied by means of scanning electron microscopy and Xray diffraction. It is found that the films contain Cu nanoparticles and exhibit preferred orientation, which are related with the current density, the orientation and the miscut degree of the substrate. On Si(100), the texture coefficient (TC) of Cu(220) plane increases with the increase of current density. Under the same deposition conditions, Cu(220) plane is the preferential orientation plane either on a Si(111) substrate with a miscut angle less than 0.2°,or on a Si (100) substrate. However, on a Si (111) substrate with a miscut angle of 4°, the Cu(111) plane is the preferentially orientated.

Key words:Cu; electrodeposition; Sisubstrate;preferential orientation

Solvothermal Synthesis and Characterization of Bi2Te3 Nanocrystals

LIU Song1,CAO Chuanbao1, JI Fengqiu2,AN Xiaoqiang1, XU Yajie1

(1. Research Center of Materials Science, Beijing Institute of Techonology,Beijing 100081, China;

2. Department of Traffic Engineering, Shijiazhuang Railway Institute of Technology, Shijiazhuang 050043,China) (Received 7 January 2006)

Abstract:Bi2Te3 nanocrystals with different morphologies including nanoparticles, nanorods and nanosheets were synthesized via a solvothermal process with surfactant sodium dodecylsulfate (SDS) in hydrazine hydrate at 180℃ for 10h. The products were characterized by Xray powder diffraction (XRD), scanning electron microscopy (SEM),transmission electron spectroscopy (TEM),energy dispersion Xray spectroscopy (EDS). The influences of surfanctant amount and temperature on morphology of products were discussed. A possible formation mechanism is proposed.

Key words:Bi2Te3; nanocrystals; nanorods; nanosheets; solvothermal synthesis

Hydrothermal Synthesis of Rutilestructured SnO2 Nanorods

and Submicron Crystals

ZHANG Zisheng, ZHANG Xiaojun,WANG Weiwei,LI Jun, LIU Chao,WEI Zhiren

(College of Physics Science and Technology, Hebei University, Baoding 071002 ,China) (Received 20 Fe bruary 2006)

Abstract:The SnO2 nanorods with rutile structure and diameters of 510 nm and lengths of 30100 nm were synthesized at 180℃ for 8 hours with SnCl4·5H2O as precursor at high acidic solution . When the NaOH was added as mineralizer, the long nanorods crystal with diameters of 10 20nm and lengths of 200 nm were synthesized in high alkaline solution by hydrothermal method. The submicron SnO2 crystals were synthesized at 430℃ for 24 hours with 3mol/L NaOH as mineralizer by hydrothermal method,the maximum length is 300nm.

Key words:SnO2; hydrothermal synthesis; nanorods; crystals

Synthesis of ptype ZnO Thin Films and Influence of Substrate

Temperature on Their Properties

FAN Hongbing1,2,ZHANG Xiaodan2 ,ZHAO Ying2 ,SUN Jian2 , WEI Changchun2 ,GU Shibin1, ZHANG Cunshan1

(1. College of Information Engineering, Hebei University of Technology, Tianjin 300130, China;

2. Institute of Photoelectronics Thin Film Devices and Technique of Nankai University,

Key Laboratory of Photoelectronics Thin Film Devices and Technique of Tianjin, Nankai University

Key Laboratory of Optoelectronic Information Science and Technology (Nankai University,Tianjin University), Ministry of Education,Tianjin 300071, China)

(Received 25 January 2006)

Abstract:Series of ZnO thin films were deposited at different substrate temperatures by the improved ultrasonic spray pyrolysis method. It was mainly focused on the electrical and structural properties of thin films. The results of Hall measurement demonstrated that p type ZnO was fabricated, which have high carrier concentration of 1.30×1019cm3.The results of XRD and SEM analysis reveal that ZnO thin films grown at 450℃ possess the best crystal quality.

Key words:ZnO; ptype conduction; ultrasonic spray pyrolysis; substrate temperature

Study on Preparation and Properties of Ni3Al/HAP Bioceramics Composite

SUN Chang,SUN Kangning,LI Aimin,LIU Aihong,LIU Xiaofei

(Key Laboratory of Liquid Structure and Heredity of Materials,Ministry of Education,

Key Labortory of Engineering Ceramics of Shandong Province, Shandong University, Jinan 250061,China) (Received 5 December 2005,accepted 10 April 2006)

Abstract:This paper studied the preparation and properties of Ni3Al/HAP bioceramics composite. The phase of biocomposites was studied by XRD. The biocompatibility of Ni3Al/HAP composite was evaluated with the histological methods. The study showed the bioceramic composite had good mechanical properties and biocompatibility.

Key words:HAP; Ni3Al/HAP; bioceramics;composites

Fitting Function of Potential Energy of H2 out of Sidewall in the H2

Storage of Singlewalled Carbon Nanotubes

GUO Lianquan1, MA He1, WANG Shuai1, HAN Dong1, LI Xin2

(1. School of Sciences, Shenyang University of Technology, Shenyang 110023, China; 2. School of Basic Courses, Shenyang Pharmaceutical University, Shenyang 110015, China)

(Received 21 July 2005)

Abstract:The potential energy curve between H2 and carbon nanotubes is an important antente in the field of hydrogen storage simulation and building the formula about the potential energy curve has value in the theoretical research and practical application. In this paper, potential energy model between H2 and carbon atom was built with LennardJones potential energy by using molecular dynamics, and the potential energy curve between hydrogen molecules and carbon nanotube was computed. We acquired optimal parameters through fitting the curve of H2 potential energy outside the tube, and got the formula of H2 potential energy outside the tube, this found the place of maximum storing hydrogen capacity outside SWNT,which provided the theoretical reference for the study of the SWNTs.

Key words:carbon nanotubes; hydrogen storage; potential energy; fitting function; computer simulation

Study on Preparing Nanosized ZrO2 by Different Techniques

WANG Huanying1,GUO Zhansheng1,XING Guangen1,SONG Xiuqin2

(1.Department of Application Chemistry,Hengshui College, Hengshui 053000,China;

2.Department of Chemistry,HeBei Normal University,Shijiazhuang 050016,China) (Received 6 January 2006,accepted 20 April 2006)

Abstract:Nanozirconia was prepared by chemical precipitation process(positive and reverse),homogeneity precipitation method and hydrothermal process in this work.The influence of different techniques on particle size ,powder reunite and shapes was studied. The conclusion is that nanozirconia obtained by the reverse chemical precipitation method has smaller size particles and good homogeneity, microwave heating is better than general heating.The influence of the additive on nanosized ZrO2 powder was disscused.

Key words:nanosized ZrO2; chemical precipitating process; hydrothermal process

Physical Properties of ZnO:Al Films by DC Magnetron

Sputtering with Facing Targets

LI Wei, SUN Yun, HE Qing, LIU Fangfang, LI Fengyan

(Institute of Photoelectronic Thin Film Device and Technology, Nankai University, Tianjin 300071, China;

Key Laboratory of Photoelectronics Thin Film Devices and Technology of Tianjin,Tianjin 300071,China)

(Received 26 December 2005)

Abstract:In this study, DC magnetron sputtering from ceramic targets in argon atmosphere with facing targets was used for ZnO:Al(ZAO)thin film deposit. It can reduce the effect of the bombardment of the plasma on the base thin films using the facing targets. The ZAO thin films have high quality, such as high crystallinity, low resistivity, and high mobility. The lowest resistivity is 4.47×104Ω·cm. The optical transmittance of the ZAO thin films in the visible range is over 85 %. Therefore, the ZAO thin films are more suitable for the window layers of the CIS thin films solar cells.

Key words:facing targets; magnetron sputtering; ZnO:Al

Nonpolar GaN Films and Their Substrate

ZHOU Jianhua1,2,ZHOU Shengming1,ZOU Jun1,2, HUANG Taohua1,2, XUN Jun1,

XIE Zili3,HAN Ping3, ZHANG Rong3

(1.Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sicences,Shanghai 201800,China;

2.Graduate School of the Chinese Academy of Science,Beijing 100039,China;

3.Department of Physics, Nanjing University,Nanjing 210093,China) (Received 18 November 2005,Mccepted 12 uarch 2006)

Abstract:This review focuses mainly on the GaN films deposited on a variety of substrates, γLiAlO2 and rplane sapphire especially.GaN films on sapphire are commonly grown in the polar c([0001]) direction,which leads to a strong internal electrostatic field in quantum wells based on GaN,and hence decreasing the intensity of luminescence. Epitaxial growth of nonpolar wurtzite GaN films provides a promising means of circumventing the physical phenomenon and a good performance in visible band.

Key words:rplane sapphire; γLiAlO2;aplane GaN; mplane GaN

Reduction of Cracks in GaN Film Grown on Si(111) by

Lowtemperature AlN Interlayer

FENG Yuchun,LIU Xiaofeng,WANG Wenxin,PENG Dongsheng, GUO Baoping

( Institute of Optoeletronics,Shenzhen University,Key Laboratory of Optoeletronic Devices and Systems,Guangdong Province, Key Laboratory of Optoeletronic Devices and Systems,Ministry of Education,Shenzhen 518060,China)

(Received 4 November 2005,accepted 20 February 2006 )

Abstract:The lowtemperaturedeposited(LT) AlN layer was inserted into hightemperaturedeposited (HT) GaN layer in order to reduce stress and cracks of GaN film grown on Si(111) by MOCVD. Lowtemperature AlN interlayer can balance HTGaN layer tensile stress which is aroused during the course of deposition and temperaturefalling, and reduce cracks of thick film. The crackfree GaN film with thickness over 1.8μm is grown triumphantly. The influence of lowtemperature AlN interlayer deposited temperature on GaN film was studied emphatically in the paper, and the optimum deposited temperature of LTAlN is given. The microstructures of samples were studied by scanning electron microscopy(SEM), atomic force microscopy(AFM) and highresolution double crystal Xray diffraction(DCXRD). The result shown that LTAlN deposited temperature is very important. The crystal quality of GaN film is inferior even crystal can not be formed if the temperature is too lower. The crystal quality of GaN film is inferior too, and the stress balance influence of LTAlN is reduced if the temperature is higher. We can conclude that the optimum deposited temperature of LTAlN is about 680℃.

Key words:Si(111);GaN;AlN

Preparation of Flaky Carbon Nanomaterials by Thermal

Chemical Vapor Deposition

LI Minghua ,ZHANG Haiyan , WEI Aixiang ,CHEN Yiming ,WANG Li ,ZHU Qingfeng

(Faculty of Material and Energy, Guangdong University of Technology, Guangzhou 510006,China)

(Received 20 Janaury 2006,accepted 24 February 2006)

Abstract:The anodic aluminum oxide (AAO) template was fabricated by twostep anodization process of aluminium with oxalic acid .The aperture of this AAO templates is about 100nm.The strawy flaky carbon nanomaterials were successfully grown on the edge of alumina template nanopores by thermal chemical vapor deposition (TCVD) catalyzed with alumina itself. The structures of alumina template and strawy flaky carbon nanomaterials were characterized by field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The growth mechanism and formation condition of strawy flaky carbon nanomaterials were discussed. It provides some significance for the preparation of tubal, flaky and clubbed carbon nanomaterials with the AAO templates.

Key words:anodic aluminum oxide( AAO )template ; thermal chemical vapor deposition (TCVD); flaky carbon nanomaterials

Effect of Different Coupling Widths on Induction Heating in the

Large Size SiC Growth System

ZHANG Qunshe, CHEN Zhiming, LI Liuchen,PU Hongbin, FENG Xianfeng, CHEN Xi

(Department of Electronic Engineering, Xian University of Technology, Xian 710048, China)

(Received 24 March 2006,accepted 28 April 2006)

Abstract:The influences of different coupling widths of the heating subassembly on the induction magnetic field, induction current and Joule heat in the large size SiC growth system have been investigated systematically. By comparing of the time of heatingup for quasistationary state of growth system, it can be concluded that induction heating efficiency can be increased while the time of heatingup stage can be shortened in the growth system, assuming that the RF power, frequency and turns of coil are constant.

Key words:SiC; PVT method; magnetic potential; Joule heat

Research and Development of Infrared Nonlinear Optical Crystals

DONG Chunming, WANG Shanpeng, TAO Xutang

(State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100,China)

(Received 31 May 2006)

Abstract:The research and progress of several important midinfrared nonlinear optical crystals were reviewed in this paper. The crystal structure, nonlinear optical properties and the important applications of these crystals were introduced. We also present the difficulties encountered during the process of crystal growth. And the approaches to solve these difficulties were discussed. We believe that it is much valuable to obtain nonlinear optical crystals with good quality and suitable size. Finally, we discussed the future study of the infrared nonlinear optical crystals.

Key words:midinfrared; frequency conversion; nonlinear optical crystals

Study on Sintering Process of MnZn Ferrite Nanopowders

and Its Sintered Properties

CUI Yinfang, WANG Xin, JIANG Yanfei, LI Yangxian

(School of Material Science and Engineering, Hebei University of Technology, Tianjin 300130,China)

(Received 23 January 2006)

Abstract:The segmented sintering process with different sintering temperature and grain growth of MnZn ferrite nanopowders are investigated in this paper. The density, microstructure and phase composition of sintered compacts of MnZn ferrite nanopowders were measured by Archimedes method, Xray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results show that the density of sintered compacts of MnZn ferrite nanopowders increases with the rising of the sintering temperature. The compact sintered at 900℃ achieves the optimal density of MnZn ferrite needed. The grain size can be estimated from the \[311\] peak by the Scherrer equation and it is 54.9nm when sintered at 900℃. Additionally, from the fractured surface of sintered samples, it can be seen that the grains grow very well with small grain size and homogeneous distribution.

Key words:MnZn ferrite nanopowders; sintering process; the density of sintered compact of MnZn ferrite; grain growth

Influence of Sr2+ on Crystal Growth and Raman Properties

of GdVO4 Single Crystal

ZHONG Fulan, ZHU Jin, CHEN Jianzhong, ZHUANG Naifeng

(Institute of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350002,China) (Received 28 December 2005)

Abstract:The paper reported the influence of Sr2+doped ion on crystal growth and Raman properties of GdVO4 single crystal. The powder of SrxGd1xVO4 crystals was measured by Xray diffraction, which showed asgrown crystals have a zircontype structure belonging to tetragonal system. Sr2+ ion substituted difficultly for Gd3+when concentration is higher, which resulted in the formation of crack and inclusion in SrxGd1xVO4 crystals. The XPS experiments proved that the V element of SrxGd1xVO4 crystals remained in the pentavalent. The Raman spectra of SrxGd1xVO4 crystals were measured at room temperature. The results indicated that Sr2+doped ion strengthened the peak of VO4 at 884cm1, and influenced the Raman properties of GdVO4 single crystal.

Key words:SrxGd1xVO4 crystals; crystal growth; Raman spectrum

Raman Spectra Study of Thermal Conductivity of

Nddoped Vanadate Crystals

ZHAO Peng,ZHANG Haikun,SU Yan,ZHOU Cheng,REN Miaojuan,ZHANG Zhong

(Physics Department,School of Science, Jinan University, Jinan 250022,China)

(Received 19 September 2005)

Abstract:Based on the lattice dynamics theory, we got a correlation between the thermal conductivity and the Raman scattering integrated intensity. The Raman spectra and thermal conductivities along adirection and cdirection of NGV and NYV were measured, respectively. The results are agreement with the correlation.

Key words:Raman spectra;vanadate crystal;thermal conductivity

Hydrothermalhomogenous Precipitation Method Synthesis of

Zr(OH)x/NH4Cl Compound Dendrite Like Crystals

SUN Xiaofei, SONG Xiuqin

(Department of Chemistry and Material Science,Hebei Normal University,Shijiazhuang 050016, China) (Received 10 January 2006,accepted 20 March 2006)

Abstract:A novel Zr(OH)x/NH4Cl compound dendritelike crystals were synthesized by hydrothermalhomogenous precipitation method,using ZrOCl2·8H2O and CO(NH2)2 .The prepared products were characterized by means of Xray diffraction, transmission electron microscopy, scanning electron microscopy and energy dispersive spectrum. We conclude from the results that NH4Cl had important influence on the formation of compound dendritelike crystals. Zirconia precursor is enwraped by NH4Cl,and NH4Cl growth by the crystal growth method.

Key words:zirconia; dendrites; hydrothermal method; homogenous precipitation method

Platelike SrBi4Ti4O15 Powder Synthesized by Molten Salt Method

ZHANG Ke,HUANG Jinliang, LI Lihua

(School of Material Science and Engineering, Henan University of Science and Technology, Luoyang 471003,China)

(Received 9 January 2006,accepted 21 February 2006)

Abstract:Platelike SrBi4Ti4O15 powder with anisotropy was synthesized by NaClKCl molten salt synthesis method (MSM). The phases of the reaction products and the microstructures at different calcined temperatures were detected by Xray powder diffraction(XRD) and scanning electron microscope (SEM), respectively. The effects of calcined temperatures on microstructure and morphology of SrBi4Ti4O15 powder were investigated. Comparing to conventional solid phase process (CS), the powder synthesized by MSM was oriented at (00l) grain plane. During 8501050℃,the flake structure of powder was much more distinct and the level of anisotropy increasing first, and then decreasing with the temperature increased. The best calcined temperatures of platedlike SrBi4Ti4O15 powder with anisotropy was from 900 to 1000℃.

Key words:molten salt method, SrBi4Ti4O15; preferred orientation; flake structure

Twowave Coupling and Image Storage in Cr:KNSBN Crystal

GUO Qinglin, WEI Lijing, SU Hongxin, GUO Jianxin, ZHANG Jinping, HUAI Sufang, FU Guangsheng

(College of Physics Science and Technology, Hebei University, Baoding 071002, China)

(Received 9 December 2005,accepted 7 January 2006)

Abstract:By using the extraordinary polarized HeNe 632.8nm laser beam in the Cr:KNSBN crystal, the transmitted intensity of pump beam and signal beam as a function of time in the twowave coupling process were experimentally investigated, and the transmitted intensity of pump beam as a function of time was also investigated when the signal beam was shutted. It is shown that the lost pump beam energy was totally transferred into the signal beam without scattering beam. An image storage experiment of a binary image was performed, and a clear reconstructed image with high signaltonoise ratio and without scattering beam impacting was obtained.

Key words:Cr:KNSBN crystal; twowave coupling; beam fanning effect; image storage

Research on Dielectric Property of Fine Zn(Al)O by Citrate Gel Method

ZENG Guoxun, ZHANG Haiyan, HU Lichu, WANG Li, CHEN Yiming

(Faculty of Material and Energy, Guangdong University of Technology,Guangzhou 510640,China)

(Received 6 January 2006)

Abstract:Zn(Al)O are good infrared camouflage materials. In this paper, Zn(Al)O was prepared by citrate gel method. The XRD result indicates that the single phase of Zn(Al)O can be manufactured by this method, but it is not pure — containing black carbon, and these carbon disappear by holding at 600℃ in 90min.The complex permittivities show that the values of Zn(Al)O containing black carbon are higher than pure Zn(Al)O in the band of 218GHz.Both of Zn(Al)O and Zn(Al)O with black carbon have two peaks of imaginary parts at X and Ku band. The peak at X band is easily affected by black carbon, but the peak at Ku band doesnt. The microwave reflection loss of Zn(Al)O has been simulated by Transmission Line Modeling. The results indicate Zn(Al)O dont affect the microwave absorption of the next coating when they are used to be infrared camouflage surface coating.

Key words:Zn(Al)O;microwave; dielectric property

Blue Lightemitting Properties of Nanofilm Materials

and Their Research Progresses

PENG Yingcai1,2, FU Guangsheng3, WANG Yinglong3

(1.College of Electronic and Informational Engineering, Hebei University, Baoding 071002, China;

2.Key Laboratory of Semiconductor Material Sciences, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China;

3.College of Physical Science and Technology, Hebei University, Baoding 071002, China)

(Received 28 November 2005,accepted 8 January 2006)

Abstract:Blue lightemission is an important subject in the luminescent propertics of semiconductor materials. In the paper, we briefly introduce the physical mechanisms of blue lightemission, then some new progresses of blue lightemitting nanofilm materials, such as ncZnO、ncGaN、ncCdS and ncSi were reviewed. Finally, we predicted their developed tendency in the future.

Key words:nanostructures; blue lightemission; device applications

Influences of Dye Adsorption on Surface Structure of AgCl Cubic Microcrystal

LI Xiaowei, LI Li, ZHANG Rongxiang, ZHANG Jixian, JIANG Xiaoli, YANG Shaopeng

(College of Physics Science and Technology, Hebei University, Baoding 071002, China)

(Received 24 January 2006)

Abstract:The spectrum of the photoelectron decay in the AgCl microcrystal was measured by microwave absorption dielectric spectrum technique, combining the equation of photoelectron decay dynamics, the parameters of electron traps which were in the surface and inner of the microcrystal were determined. Then the influences of dye adsorption on surface structure of microcrystal were analyzed. It is found that not only the interstitial silver ions are produced but also the traps in the surface of microcrystal are modified when the dye is adsorbed to the surface of microcrystal. Along with the decrease of dye, the first function degenerates and disappears at last, while the second one appears and boosts up to the most until the interstitial silver no longer appear. Then with the decrease of dye the second function begins die down.

Key words:electron trap; dye adsorption; silver halide microcrystal; surface structure; surface modification

Mechanical Properties and Microstructure of Al2O3/TiB2/AlN/TiN

Composite Ceramic Materials

LIU Changxia1, ZHANG Jianhua1, SUN Junlong1, ZHANG Xihua2

(1.School of Mechanical Engineering, Shandong University, Jinan 250061, China; 2.College of Materials Science and Engineering, Shandong University, Jinan 250061, China) (Received 12 December 2005)

Abstract:In the present work, Al, Al3Ti and TiB2 are incorporated into alumina matrix ceramic materials in the form of AlTiB master alloys. Composite of Al2O3/TiB2/AlN/TiN are fabricated by the technology of transitory liquid phase sintering, during which new phases of AlN and TiN are respectively produced by the chemical reactions taking place among Al, Ti and N2 (the protective atmosphere). The hardness, the fracture toughness and the bending strength of the composites are tested. Meanwhile, the relations of volume content of AlTiB master alloys and mechanical properties of alumina matrix ceramic materials are analyzed. The effects of fracture mechanism on the mechanical properties of the composites are researched together with the refining performances of AlTiB master alloys.

Key words:Alumina; AlTiB master alloys; composite ceramic; refining performances

Progress in Study on Antiferroelectric Materials based on PZT

XIA Zhiguo, LI Qiang

(Department of Chemistry, Tsinghua University,Beijing 100084,China)

(Received 16 November 2005)

Abstract:The antiferroelectric materials based on lead zirconate titanate (PZT) are briefly reviewed. The typical antiferroelectric materials, PZT95/5, tin modified lead zirconate titanate (PZST) and its modifications, Lead lanthanum stannate zirconate titanate(PLZST) are summarized, respectively. High zirconium content PZT and PZST powders, ceramics and films doped by La3+,Nb4+,Hf4+,Sr2+,Ba2+ and Nd3+ are summed up, as well as their modification principles, preparation and properties. Based on these, the mechanisms and transition properties of ferroelectric (FE) to antiferroelectric (AFE) phase transitions in various of PZTbased antiferroelectric materials are discussed. Further aspects of research and future development about PZTbased antiferroelectric materials are proposed.

Key words:antiferroelectric materials; ferroelectricantiferroelectric phase transitions; PZT95/5;PZST;PLZST

Influence of Sintering Technique on Mechanical Properties

and Microstructure of B4C/TiB2/Mo/C Composite

SUN Junlong, DENG Jianxin, LIU Changxia

(School of Mechanical Engineering, Shandong University, Jinan 250061,China)

(Received 22 December 2005)

Abstract:80.6wt.%B4C/11.6wt.%TiB2/4.7wt%Mo/3wt.%C ceramic composite is fabricated by hotpressing sintering and the effect of sintering temperature, holding time and pressure on mechanical properties and microstructure of the composite are analyzed. The temperature is raised from 1800℃ to 1950℃, the holding time ranges from 15min to 60min and the pressure is 3035MPa. The strength, hardness, toughness and densification of the composite prepared by the optimized process of 1900℃ under 35MPa for 45min are 705MPa, 20.6GPa, 3.82MPa·m1/2, 98.2%, respectively.

Key words:B4C; sintering technique; mechanical properties; microstructure

制备工艺对B4C/TiB2/Mo/C陶瓷复合材料力学性能和 显微结构的影响

孙军龙, 邓建新, 刘长霞 (山东大学机械工程学院, 济南 250061)

摘要:采用热压法制备了80.6%B4C/11.6%TiB2/4.7%Mo/3%C质量分数陶瓷复合材料,分析了烧结工艺对力学性能和微观结构的影响。烧结温度变化范围是1800~1950℃,保温时间变化范围是15~60min,烧结压力30~35MPa。当烧结参数为1900℃、45min、35MPa,B4C/TiB2/MolC陶瓷复合材料抗弯强度、硬度、韧性、相对密度分别为705MPa、20.6GPa、3.82MPa·m1/2、98.2%。 关键词:B4C;烧结;力学性能;微结构

Dielectric Relaxation and Ferroelectric Phase Transition of Tetragonal

Structure NBTKBT Leadfree Ferroelectricity

LI Yueming1, CHEN Wen2, XU Qing2, JIANG Xiangping1, ZHANG Yuping1

(1. Jingdezhen Ceramic Institute, Jingdezhen 333001, China;

2. Institute of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China)

(Received 9 January 2006,accepted 9 April 2006)

Abstract:In this paper, the hysteresis loops and XRD patterns at different temperatures as well as dielectric constant as a function of temperature for (Na1xKx)0.5Bi0.5TiO3 (x=0.22,0.26, 0.30) ceramic composites with tetragonal symmetry structure were investigated. It is found that the tetragonal structure composites are antiferroelectric, but the composite near to the morphotropic phase boundary(MPB) showed ferroelectric characteristic because the antiferroelectric to ferroelectric phase transition was induced under electric field. The intense dependence of dielectric constant to frequency shows these materials are relaxor ferroelectric, and the appearance of the dielectric peak at heating process is caused by the transition of antiferroelectric macrodomain to microdomain.

Key words:sodiumbismuth titanate;potassiumbismuth titanate;antiferroelectric phase transition;dielectric relaxation

Growth of Co2+:BeAl2O4 Crystal by Czochralski Method and Their Spectroscopy

XIA Haiping, ZHANG Xinmin, ZHANG Yuepin, ZHANG Jianli,WANG Jinhao

(Key Laboratory of Photoelectronic Materials, Ningbo University, Ningbo 315211, China)

(Received 9 December 2005,accepted 7 January 2006)

Abstract:The Co2+:BeAl2O4 crystal, initial doped Co2+ ion of 0.15 mol%, in the size of 48×85mm2 with high quality was grown by the Czochralski (CZ) technique under the optimized conditions of choosing proper raw chemical compositions, taking reasonable melting process of the raw materials, using favorable temperature gradient of solidliquid interface and growth rate. The absorption spectrum of Co2+:BeAl2O4 crystal was measured, and two main peaks at 496 and 640nm were observed. The peaks at 496 and 640 nm are assigned to the4T1(4F)→4T1(4P) transition of Co2+ located in octahedral sites, and 4A2(4F)→4T1(4P)of Co2+ in tetrahedral sites, respectively. It could be deduced from the characteristics of absorption spectrum and their pink color of crystal that the majority of Co2+ ions substituted the Al3+ in BeAl2O4 crystal to form octahedral sites. The emission spectra of crystals in the visible region were investigated under excited with various lights, and the emission band 678nm was observed. The emission band at 678nm is assigned to the 4T1(4P)  4A2(4F) transition of Co2+ ions in tetrahedron.

Key words:BeAl2O4 crystal; Czochralski method; Co2+ ion; spectra

Pointseed Growth and Defects of KDP Crystal

LI Xiaobing, TENG Bing,ZHONG Degao, LU Xiaodong, ZHUANG Yan

(Physics Department of Qingdao University, Qingdao 266071,China)

(Received 18 December 2005)

Abstract:The pH value of solution influences the growth habits of KDP crystal, about which the crystal growth experiments and the parameter comparison was completed. KDP crystals were grown in the solution with low supersaturation and comparatively high pH value. The defects and the cation content in different crystal positions were analyzed. It is indicated that pH value of the solution makes an obvious effect on the relative growth speed of crystal faces. The KDP crystal with the size of 50×50×50mm3 was grown in the condition of pH=5.0 and low supersaturation(σ<0.02).

Key words:KDP crystal; point seed; pH value; defects; cation content

Transmission Spectrum of Multiquantum Well Structure

with Thicknessmodulated Dualperiodically

WANG Tongbiao,LIU Xiaoliang, YIN Chengping,LIU Nianhua

(Department of Physics , Nanchang University ,Nanchang 330047,China)

(Received 13 December 2005,accepted 13 January 2006)

Abstract:The transmission spectrum of multiple quantum well structure with thicknessmodulated dualperiod was studied by means of transfer matrix method. Some narrow bands appear in the gap of the simple multiquantum well structure of singleperiod. The wave function in the narrow bands are localized.

Key words:dualperiod; quantum well;localization

Preparation and Characterization of Electrodeposited CdS Thin Films

GE Yanhui, SHI Weimin, WEI Guangpu, XU Jing, QIU Yonghua

(Department of Electronic Information Materials, Shanghai University, Shanghai 200072, China)

(Received 23 October 2005,accepted 22 November 2005)

Abstract:CdS thin films were obtained by electrodeposition. The structure and surface morphology of the films was studied by Xray diffraction (XRD) and scanning electron microscope (SEM) method respectively.The influence of different applied potential and temperature on the stoichiometry of the CdS films was investigated. The optimal applied potential was about 2.53.0V. The solar cells with the structure of ITO/nCdS/pSnS/Ag have been made. The photovoltaic properties of a opencircuit voltage of 0.2V, a shortcircuit current of 13.2mA/cm2, a filling factor of 0.31, and a conversion efficiency of 0.81% were obtained under the illumination of 100mW/cm2.

Key words:CdS; electrodeposition; solar cellsInfluences of Different Fluxes on Synthesis of the Red Long Afterglow

Phosphor Gd2O2S:Eu,Mg,Ti by the Microwave Radiation Method

ZHAI Yongqing,LIU Yuanhong

(College of Chemistry and Environmental Science, Hebei University, Baoding 071002,China)

(Received 23 December 2005)

Abstract:Gd2O2S:Eu,Mg,Ti, a novel red phosphor was firstly synthesized in microwave field. The synthesized phosphors were investigated by XRD, SEM and Fluorescence spectrophotometer respectively. The influences of five fluxes of Li2CO3, Na2CO3, K2CO3, Na3PO4, K2HPO4,and complex flux of Li2CO3 and Na2CO3 on the structure, micrograph and luminescent properties of Gd2O2S:Eu,Mg,Ti phosphor were studied. The results indicate that single phase Gd2O2S:Eu,Mg,Ti could be obtained by adding different fluxes. Gd2O2S:Eu,Mg,Ti phosphors possess hexagonal crystal structure, which is similar to that of Gd2O2S. The dispersity is well,and the grain size and micrograph of the samples are different with different fluxes. Emission spectra show that the intensity of emission peak at 627 nm depends greatly on the added flux, but their shape and position are the same basically . Excitation spectra show similar phenomenon. Furthermore adding two fluxes, Li2CO3 and Na2CO3 can improve decay time effectively.

Key words:flux; Gd2O2S:Eu,Mg,Ti; microwave method; spectram; long afterglow

Controlled Growth of Micrometer Tubular ZnO

YANG Liping , LI Yan ,DENG Hong

(School of Microelectronics and Solid State Electronics, University of Electronic Science and Technology of China,Chengdu 610054,China)

(Received 23 October 2005)

Abstract:Micrometer tubular ZnO was synthesized on glass substrate by hydrothermal method. Scanning electron microscopy (SEM) and Xray diffraction (XRD) have been used to characterize structure and surface morphology of the tubular ZnO. XRD indicated that products were wurtzite zinc oxide.We can obtain micrometer tubular ZnO by laying ZnO on glass in advance. The controlled growth of tubular ZnO has been realized preliminarily by setting the grain size of ZnO layer.

Key words:ZnO; micrometer tubular; controlled growth

Theoretical Research on Stability and Capability of Silicon Nanotubes

LI Xiaoxiang, TANG Yuanhong, PEI Lizhai

(College of Materials Science and Engineering, Hunan University, Changsha 410082, China)

(Received 26 December 2005)

Abstract:Silicon nanotube is a kind of brandnew nanomaterial following carbon nanotube and silicon nanowire. The recent theoretical developments of silicon nanotube were introduced in this paper. The stability, stability formation, capability including conductivity, caloric characters and mechanical property of silicon nanotube were demonstrated respectively. At last, the promising prospect of silicon nanotube was discussed.

Key words:silicon nanotube; stability; property

Preparation of NiZrO2 Nanocomposite Electroforming Deposits and

Research of Distribution of Nanoparticles

ZHANG Wenfeng1, 2,ZHU Di1

(1. Department of Mechanical and Electrical Engineering, Suzhou Vocational College, Suzhou 215011, China;

2. College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)

(Received 7 September 2005)

Abstract:In the composite electroforming, when other process parameters were remained stationary, the variable tendency of codeposition rate and thickness of nanocomposite electroforming deposits were investigated. SEM and EDS were used for the examination of surface morphology and the component of nanocomposite electroforming deposits. Distribution of nanoparticles in surface and crosssection of nanocomposite electroforming deposits was surveyed. Results indicate that the nanocomposite electroforms composed by matrix metal Ni and ZrO2 nanoparticles exhibit a smooth surface and compact microstructure, the nanoparticles are dispersed inside the metallic matrix.

Key words:compositeelectroforming; nanoparticle; surface morphology; structure content; uniformity

Preparation of the Ultrafine CeO2 Powder by Homogenous

Precipitation Method with DMO

MEI Yan, HAN Yebin, NIE Zuoren

(College of Materials Science and Engineering, Beijing University of Technology, Beijing 100022, China)

(Received 24 November 2005, accepted 21 February 2006)

Abstract:Ultrafine CeO2 powder was prepared by using Ce(NO3)2·6H2O as a source and dimethyl oxalate(DMO) as an internal precipitator. The precursor suspension at different reaction time and subsequent calcination powders were analyzed by XRD, TEM, ED and SEM. The results show that calcined cerium powders are similar in the size and morphology to the precursors Ce2(C2O4)3·10H2O. Namely, the size and morphology of CeO2 inherit the precursors. Acordingly, it’s possible to control the reaction condition so as to dominate the final outcomes. In this way, the particle morphology of prepared CeO2 powders is blocklike with the size of about 1μm and dispersed equably.

Key words:dimethyl oxalate (DMO); homogeneous precipitation method; ultrafine; cerium oxide

Anisotropic Absorption Spectra and Upconversion of Nd3+∶KGW Crystal

LIU Jing1, ZHENG Zhiqiang1, HUANG Shujie1,LI Xiaoyan1,FENG Zhuohong1,

HONG Jinmian1,LIN Lin1,Ming Hai2

(1.School of Physics and Optoelectronics Technology, Fujian Normal University, Fuzhou 350007,China; 2. Department of Physics, University of Science and Technology of China,Hefei 230026 , China )

(Received 31 October 2005, accepted 23 January 2006)

Abstract:Absorption spectra of Nd3+:KGW crystal for the three crystallographic axes were investigated at room temperature. The absorption band intensities distinctly revealed the anisotropy of Nd3+:KGW. The JuddOfelt theory was modified and applied to the treatment of the anisotropic absorption spectra. The absorption coefficients and the electric dipole oscillator strengths of various bands were calculated for three crystallographic axes of Nd3+:KGW crystals. The results indicate the anisotropy of the optical absorption of Nd3+:KGW. The validity of the modified JuddOfelt approach is discussed in detail. Moreover ,we report the upconversion luminescence of Nd3+:KGW crystal pumped with 812nm wavelength .The analysis reveals that Nd3+:KGW crystal has potential use in blue emitting upconversion materials.

Key words:Nd3+:KGW;absorption spectra;anisotropy;upconversion

Chinese Alchemy and Vaporgrowth of Crystals

JIANG Wanli1,2, ZHANG Xiwei2

(1. State Key Laboratory of Crystal Materials, Shandong University,Jinan 250100, China;

2. School of History and Culture, Shandong University,Jinan 250100,China)

(Received 3 April 2006)

Abstract:Origin, development, and decline of alchemy in China were briefly reviewed.In this paper the contribution of Chinese ancient alchemy to Chinese material medica, mineralogy, modern chemistry, and vaporgrowth of crystals was presented and discussed. After collection and collation of scraps of ancient references about alchemy, the authors gave a general picture of vaporgrowth of crystal in ancient time in China. The relationship between alchemy and vaporgrowth of artificial crystals was explored, and the reason of decline of Chinese alchemy was given. It is concluded that vaporgrowth of artificial crystals originated from Chinese ancient alchemy and vermilion (artificials cinnabaris),and was the earliest artificial crystal grown through a vaporgrowth method.

Key words:alchemy;vaporgrowth;artificial crystals