The influence of La-substitution on the micro-structure and ferroelectric properties of chemical-solution-deposited BiFeO3 thin films
The influence of La-substitution on the micro-structure and ferroelectric properties of chemical-solution-deposited BiFeO3 thin films
复制标题
DOI：
10.1088/0022-3727/40/9/004
复制
发表时间：
2007-05
期刊：
影响因子：
--
通讯作者：
S. Singh;K. Maruyama;H. Ishiwara
中科院分区：
文献类型：
--
作者：
S. Singh;K. Maruyama;H. Ishiwara
采用溶胶-凝胶法在Pt/Ti/SiO2/Si（100）结构上制备了La掺杂的BiFeO 3（BFO）薄膜。在BFO薄膜中，La原子取代量高达20%时，没有观察到第二相。随着La掺杂浓度的增加，薄膜的微结构发生了变化，从而影响了薄膜的铁电性能。BFO薄膜的介电常数在1 MHz时约为90，而在20%La取代的BFO薄膜中增加到125，这可能是由于晶粒的尺寸效应。La原子在BFO薄膜中的替代降低了漏电流和反向极化。当在20 kHz以上测量磁滞回线时，磁滞回线中的漏电流贡献可忽略不计。在100 kHz下，在5%La取代的BFO膜中获得的饱和反射极化为50 µC cm−2。
La-substituted BiFeO3 (BFO) thin films were formed by depositing sol–gel solutions on Pt/Ti/SiO2/Si (1 0 0) structures. No secondary phase was observed by La-atom-substitution up to 20% in BFO thin films. The micro-structures of the films were changed with an increase in La concentration, which influenced the ferroelectric properties of the films. The dielectric constant of a BFO film was approximately 90 at 1 MHz and it increased to 125 in a 20% La-substituted BFO film, which was probably due to the size effect of grains. The substitution of La atoms in BFO films reduced the leakage current as well as remanent polarization. The leakage current contribution in the hysteresis loop was negligible when the loops were measured at above 20 kHz. The obtained saturated remanent polarization was 50 µC cm−2 in a 5% La-substituted BFO film at 100 kHz.