Ferroelectric property of epitaxial Bi4Ti3O12 films prepared by metalorganic chemical vapor deposition
Ferroelectric property of epitaxial Bi4Ti3O12 films prepared by metalorganic chemical vapor deposition
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DOI：
10.1557/jmr.2001.0046
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发表时间：
2001-01-01
影响因子：
2.7
通讯作者：
Saito, K
中科院分区：
文献类型：
--
作者：
Watanabe, T;Funakubo, H;Saito, K
研究了Bi_4Ti_3O_（12）薄膜铁电性的取向关系。采用金属有机化学气相沉积法在（100）（c）CaRuO 3//（100）SrTiO 3、（110）（c）SrRuO 3//（110）SrTiO 3和（111）（c）SrRuO 3//（111）SrTiO 3衬底上分别外延生长了（001）、（118）和（104）取向的Bi 4 Ti 3 O 12薄膜。除了（104）取向薄膜的漏电流较大外，（001）取向和（118）取向薄膜的铁电性大小不同。对于（001）和（118）取向的薄膜，反射极化和矫顽场分别为1.5 μ C/cm（2）和15 kV/cm，16.5 μ C/cm（2）和132 kV/cm。（001）和（118）取向膜的自发极化（P-S）分别为4.0 μ C/cm（2）和27.0 μ C/cm（2）。这与SrBi_2Ta_2O_9的（001）取向的样品没有观察到铁电性的结果不同，与晶体结构的估计结果一致。沿Bi_4 Ti_3 O_（12）c轴和a轴的P-S值沿着分别为4.0和48.4 μ C/cm（2），与单晶的报道值吻合得很好。此外，两种膜在用500 kHz矩形脉冲测量的7.8 x 10（10）次开关循环后均显示出良好的疲劳耐久性。
The orientation dependence of the ferroelectricity of epitaxially grown Bi4Ti3O12 thin films was investigated. The (001)-, (118)-, and (104)-oriented Bi4Ti3O12 films were epitaxially grown on (100)(c)CaRuO3//(100)SrTiO3, (110)(c)SrRuO3//(110)SrTiO3, and (111)(c)SrRuO3//(111)SrTiO3 substrates, respectively, by metalorganic chemical vapor deposition. Ferroelectric property with different magnitude was observed for (001)and (118)-oriented films but for (104)-oriented film due to its large leakage current. The remanent polarization and the coercive field were 1.5 muC/cm(2) and 15 kV/cm, 16.5 muC/cm(2) and 132 kV/cm for the (001)- and (118)-oriented thin films, respectively. The spontaneous polarization (P-S) was 4.0 muC/cm(2) and 27.0 muC/cm(2) for (001)- and (118)-oriented films, respectively. This was different from the result of SrBi2Ta2O9 in that the ferroelectricity was not observed for (001)-oriented one, and was in good agreement with the estimation from the crystal structure. The estimated P-S values along the c and a axes of Bi4Ti3O12 were 4.0 and 48.4 muC/cm(2), respectively, and agreed well with the reported values for the single crystal. Furthermore, both films showed good fatigue endurance after 7.8 x 10(10) switching cycles measured with 500 kHz rectangular pulses.