摘要
采用溶胶凝胶法在LiNaO3(LNO)衬底上制备Na0.5Bi0.5TiO3(NBT)薄膜.部分NBT薄膜在氮气氛围下进行了热处理,记为NBT-N2.在100～400 K的温度范围内,测量了NBT-N2的介电性能.NBT-N2薄膜的介电频谱中出现了损耗峰,存在弛豫现象.利用Arrhenius公式拟合弛豫所对应的激活能,发现在NBT-N2薄膜中存在2个热激活过程:一个对应氧空位电离引入的极化子的跳跃跃迁;另一个对应导电电子与偏离氧八面体中心的Ti离子之间的耦合.此外,采用复阻抗谱分析了NBT-N2薄膜中的介电弛豫过程,在测试温度范围内,随着温度的升高,该弛豫过程逐渐趋向于理想的德拜模型.
Na0.5Bi0.5TiO3（NBT） thin films were prepared on LaNiO3-coated substrate by sol-gel method.Parts of NBT films were treated in N2 atmosphere,donating as NBT-N2.The dielectric properties of NBT-N2 films were measured in the temperature range of 100 ～400 K.The results show that NBT-N2 film exhibits a loss peak in the frequency dependence of dielectric loss,indicating a Debye-like relaxation.The activation energy for the relaxation is fitted using Arrhenius law.The fitting results imply that there are two thermally activated processes in the NBT-N2 thin film,which are ascribed to polarons induced from the formation of oxygen vacancies and the coupling effect between the conducting electrons and the off-center Ti ions,respectively.Meanwhile,the dielectric response is plotted in complex permittivity plane to analyze the relaxation process.In the measured temperature range,the relaxation process shows a trend to the ideal Debye model with increasing temperature.
出处
《南通大学学报（自然科学版）》
CAS
2013年第2期72-77,共6页
Journal of Nantong University(Natural Science Edition)
基金
上海市自然科学基金项目(10ZR1409800)
关键词
氮气氛围
热处理
Na0
5Bi0
5TiO3薄膜
低温介电性能
N2atmosphere
heat treatment
NBT thin film
dielectric relaxation
low temperature dielectric property
