Research for Physical Properties and Applications to Electronic Devices in Ferromagnetic and Ferroelectric Oxide Films Prepared by Sputtering

溅射制备铁磁、铁电氧化物薄膜的物理性能及其在电子器件中的应用研究

基本信息

批准号：
13650364
负责人：
KAJIMA Atsushi
金额：
$ 2.69万
依托单位：
Kitakyushu National College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

In Bi_2O_3-Fe_2-O_3-PbTiO_3 system thin films prepared by rf-reactive sputtering, ε_r' the real part of dielectric permittivity, was changed by applying a magnetic field H. The Δε_r' vs. H curves of the films subjected to annealing at various temperatures were strongly correlated with their magnetization properties. The maximum relative value of |Δε_r''(H)/ε_r'| reached as much as 1.0%. A ε_r''(H) curve can be reconstructed by a simple model based on uniform magnetization rotation. Next, we measured the temperature dependence of ε_r' and Δε_r'(H)- Both quantities increase rapidly above 50℃, which suggests that softening of the glass network of the dielectric matrix takes place at this temperature to promote the charge displacement giving rise to the dielectric polarization. In addition, we measured the magnetic field dependence of the displacement current Jd(H) to confirm whether the permeability change with magnetic field Δε_r''(H) is intrinsic. It was found that Jd(H) is also subject to change in a similar manner to Δε_r'(H), indicating that the charge displacement assisted by H really occurs. Finally, we observed the dielectric polarization induced by applying a small ac magnetic field at room temperature. This is considered to be a new type of electromagnetic effect. To explain the experimental results, we propose a simple model based on magnetization rotation of ferromagnetic nano-clusters dispersed in a dielectric glassy matrix.

在BI_2O_3-FE_2-O_3-PBTIO_3在通过RF反应溅射制备的系统薄膜中，ε_r'饮食介绍力的真正部分通过磁场H进行了H。Δε_R'vs.与在各种温度下具有强度较高质量质量的电影的Δε_R'vs. H曲线。 |δε_r''（h）/ε_r'|的最大相对值达到1.0％。可以通过基于均匀磁化旋转的简单模型重建ε_r''（H）曲线。接下来，我们测量了ε_r'和δε_R'（h）的温度依赖性 - 两个量迅速增加以上，这表明在此温度下进行饮食基质的玻璃网络的软化是在此温度下进行的，以促进电荷位移，从而引起字典极化。此外，我们测量了位移电流JD（H）的磁场依赖性，以确认磁场的渗透率是否随磁场变化为δε_R''（H）是固有的。发现JD（H）也可能以与δε_R'（H）相似的方式发生变化，表明由H辅助的电荷位移确实发生了。最后，我们观察到通过在室温下施加一个小的AC磁场引起的饮食极化。这被认为是一种新型的电磁效应。为了解释实验结果，我们提出了一个简单的模型，基于分散在旧的玻璃基体中的铁磁纳米群的磁化旋转。