文档介绍：
不同热解工艺对铁酸铋薄膜结构及导电机
制的影响
任银娟,朱小红**
5
10
15
20
(四川大学材料科学与工程学院,成都 610065)
摘要:采用溶胶-凝胶方法和不同的热解工艺( 350°C/3min, 350°C/90s, 350°C/45s 和
250°C/45s-400°C/45s)在(111)Pt/Ti/SiO2/Si 衬底上制备了厚度约为 300nm 的 BiFeO3 薄膜。
X 射线衍射表征说明 350°C/90s 薄膜为纯钙钛矿相, 350°C/3min , 350°C/45s 和
250°C/45s-400°C/45s 薄膜含有微量的 Bi2Fe4O9 杂相,表面形貌图证实 350°C/90s 薄膜表面
平整度最好,微观结构最致密,其他热解工艺处理的薄膜表面存在纳米尺寸的空隙和晶粒间
界。电学性能测试方面,350°C/90s 薄膜的介电常数和介电损耗受频率的影响较小,其他薄
膜的介电常数和介电损耗在低频范围时随频率的增加急剧降低。导电机制分析表明,
350°C/90s 薄膜在低、高电场范围分别符合 Ohm 导电和普尔-弗兰克导电,350°C/3min 薄膜
在低电场时由空间电荷限制导电主导,在高电场时由 Fowler-Nordheim (F-N) tunneling 导电
主导。
关键词:BiFeO3 薄膜;热解工艺;介电性质;导电机制
中图分类号:
Effects of different pyrolysis processes on structure and
conduction mechanism of BiFeO3 thin films
REN Yinjuan, ZHU Xiaohong
(College of Materials Science and Engineering, Sichuan University, Chengdu 610065)
Abstract: BiFeO3 thin films of approximately 300 nm thickness were synthesized via a simple sol-gel
25
method
and different pyrolysis processes
(350°C/3min , 350°C/90s , 350°C/45s
and
250°C/45s-400°C/45s)on (111)Pt/Ti/SiO2/Si substrates. X-ray diffraction identified that the 350°C/90s
film possessed pure single perovskite structure, whereas the 350°C/3min , 350°C/45s and
250°C/45s-400°C/45s films had tiny impure phase of Bi2Fe4O9. Morphology photographs confirmed
the best smooth surface and dense microstructure of the 350°C/90s film, while th