摘要
采用溶胶-凝胶法制备了Ba0.5Sr0.5NbzTi1-zO3薄膜(Nb=0-4.12mol%),采用HPAgilent 429A阻抗分析仪等测试方法研究了微量元素铌对Ba0.5Sr0.5NbzTi1-zO3(BSNT)薄膜介电性能的影响。当Nb分别为0-4.12mol%时,相对介电常数rε降低而介质损耗tanδ均得到了改善,当测试频率为1kHz,tanδ由0.09降低到0.067;居里温度Tm逐渐移向低温;在测试频率2.0-10MHz范围内,rε、tanδ均能表现出较好的频散特性。采用XRD、TEM等测试方法分析了薄膜的结构特征。薄膜为四方钙钛矿晶体结构,但Nb的溶入改变了晶胞参数的c/a比,减小了薄膜的晶粒尺寸,提高了薄膜的致密度。
Ba0.5Sr0.5NbzTi1-zO3（BSNT, z=0-4.12% ） thin films were prepared by sol-gel meth- od. The influences of trace element niobium （Nb） on the dielectric properties of the film were studied by means of impedance analyzer HPAgilent 4294A. The dielectric constant （εr） is reduced, but dielectric loss （tanδ） is improved, for example, tanδ is reduced from 0. 09 to 0. 067 at 1 kHz, and Curie tempera- ture Tm moves to lower temperature with the increasing amount of Nb. Better scattering frequency characteristics appear for the thin films with Nb in the range of from 2.0 MHz to 10 MHz. The microstructure of BSNT thin films was studied by XRD, TEM. The crystal structure of the BSNT thin films is tetragonal perovskit,and the grain size is decreased with the Nb content increasing. The ratios of c/a（ crystalline cell parameters） of BSNT is changed, and the density is increased.
出处
《功能材料与器件学报》
EI
CAS
CSCD
北大核心
2005年第3期308-312,共5页
Journal of Functional Materials and Devices
基金
国家重点基础研究发展计划(No.2002CB613304)
关键词
SBT薄膜
介电常数
介质损耗
Nb施主掺杂
结构特征
BSNT thin films
dielectric constant
dielectric loss
Nb dopant
characteristic microstructure
