DC Bias Voltage Dependence of Magnetic-Field-Induced Electric Polarization in Ferromagnetic Oxide Films
DC Bias Voltage Dependence of Magnetic-Field-Induced Electric Polarization in Ferromagnetic Oxide Films
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铁磁氧化物薄膜中磁场感应电极化的直流偏置电压依赖性
DOI：
10.3379/jmsjmag.28.981
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发表时间：
2004
影响因子：
--
通讯作者：
T. Fujii
中科院分区：
文献类型：
--
作者：
A. Kajima;T. Ohashi;M. Inoue;T. Fujii
在过去的几年中，我们报道了Bi_2O_3-Fe_2O_3-PbTiO_3三元系铁磁纳米复合氧化物溅射薄膜的磁化率χ'随外磁场H的变化。通过测量H辅助下的电荷位移电流和外加小交流磁场引起的电极化信号ΔPh（ω）来确定磁化率随磁场的变化Δ Ph '（H）是否为本征信号，发现ΔPh（ω）信号的变化依赖于磁场方向和垂直于薄膜平面的直流偏置电压。为了解释这些实验结果，我们对以前基于磁化旋转的模型进行了一些修改。从电容与电压的测量，它被发现，因为我们使用硅晶片作为衬底，耗尽层归因于MIS结构形成在膜-硅界面。这种效应最终可以通过施加正向偏置电场来消除。
In the past several years, we have reported that electric susceptibility χ' is subject to change with external magnetic field H in ferromagnetic nano-composite oxide sputtered films with a Bi2O3-Fe2O3-PbTiO3 ternary system. The charge displacement current assisted by H and the electric polarization induced by applying a small ac magnetic field, ΔPh(ω), were measured to confirm whether the susceptibility change with magnetic field, Δχ'(H), is intrinsic.In the present study, we found that the detected ΔPh(ω) signal changes depending on both the direction of the magnetic field and the dc bias voltage applied perpendicular to the film plane. To explain these experimental results, we made some alterations to the previous model based on magnetization rotation. From capacitance vs. voltage measurement, it was found that, since we used Si-wafers as substrates, a depletion layer attributed to the MIS structure is formed in the film-to-Si interface. This effect could ultimately be eliminated by applying a forward-biased electric field.