钛酸铅单晶纳米棒的生长机制和声子特性研究  

Growth Mechanism and Phonon Characters of Single-Crystalline PbTiO_3 Nanorods

作　　者：邓昱[1] 王金龙[2] 朱克荣[1] 周建新[1] 李政道[1] 尹真[1] 张明生[1] 

机构地区：[1]南京大学固体微结构物理实验室和现代分析中心,南京210093 [2]南京大学化学化工学院,南京210093

出　　处：《光散射学报》2006年第1期5-9,共5页The Journal of Light Scattering

基　　金：国家自然科学基金资助项目(No.10374047&No.10174034)

摘　　要：采用改进熔盐法经一步反应合成了直径50-80nm,长度为1-5μm的单晶PbTiO3纳米棒。纳米棒沿(100)晶向生长,其形成可以用Ostwald成熟机制来解释。PbTiO3纳米棒晶格结构为四方(a=b=3.926,c=3.963),与单晶相比四方性明显下降。通过变温拉曼测试发现其铁电-顺电相变温度为440℃,低于单晶(490℃)。相变过程中“软模”E(1TO)的软化行为(从67 cm-1到56 cm-1)比单晶显著减弱,表明钛酸铅纳米棒中铁电性的弱化。： We synthesized single - crystalline PbTiO3 nanorods with diameter of 50 - 80 nm and length of 1 - 5 μm through a one - step reaction in NaCl flux. The growth of the nanorods can be explained by the Ostwald ripening mechanism. The nanorods were in tetragonal structure with lattice parameters of a = 3. 926A and c = 3. 963A, respectively. Temperature dependence of Raman spectra shows that the ferro - papaelectric transition temperature of the PbTiO3 nanorods is 440℃, lower than 490℃ for bulk crystals. A weaker softening behavior of the E（1TO） soft mode has been observed in PbTiO3 nanorods （from 67 cm^-1 to 56 cm^-1） than that in crystals （from 82 cm^-1 to 45 cm^-1）, showing weakening of ferroelectricity.

关 键 词：钛酸铅单晶纳米棒 生长机制 声子特性 

分 类 号：O657.37[理学—分析化学]