基于交换偏置作用BiFeO3对NiFe2O4等磁性薄膜的电场调控

项目名称： 基于交换偏置作用BiFeO3对NiFe2O4等磁性薄膜的电场调控

项目编号： No.51302019

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 王丽丽

作者单位： 长春大学

项目金额： 25万元

中文摘要： 利用电场控制铁磁性在磁性数据存储，自旋电子学和高频磁性器件的研究领域中备受关注，采用拟磁控溅射方法制备NiFe2O4/BiFeO3异质结构薄膜，系统地研究各种实验参数对铁磁性/ BiFeO3异质结构薄膜间的界面结构、耦合和交换偏置磁学性能的影响。研究不同畴的BiFeO3及其不同的铁电反转途径对NiFe2O4/BiFeO3异质结构薄膜交换偏置的调控，实现从低温BiFeO3对交换偏置的电学调控到逐渐提高温度，获得室温或接近于室温条件下的BiFeO3对NiFe2O4/BiFeO3异质结构薄膜交换偏置的调控。探求交换偏置现象出现的根源，通过极化方向调节界面磁耦合，实现对铁磁体磁状态的控制。本项目的创新在于通过BiFeO3的铁电反铁磁强耦合机制与反铁磁和铁磁间的（交换偏置）耦合实现BiFeO3对铁磁层的电学调控，这项研究在强关联体系材料研究方面具有重要的科学意义。

中文关键词： 多铁性；BiFeO3；Fe-N铁磁层；异质结构薄膜；室温交换偏置

英文摘要： Electric-field control of magnetization has many potential applications in magnetic memory storage, sensors and spintronics. One approach to obtain this control is through multiferroic materials. We plan to obtain the fomation of a novel ferromagnetic state in the antiferromagnet BiFeO3 at the interface with ferromagnet NiFe2O4. Influence of the experimental parameters on interface structure, interface coupling and exchange bias are investigated systematically. we design an approach to control and switch local ferromagnetism with an electric field using multiferroics from the low temperature to room temperature. We use two types of electromagnetic coupling phenomenon that are manifested in heterostructures consisting of a ferromagnet in intimate contact with the multiferroic BiFeO3 to find the source of exchange bias. The first is internal, magnetoelectric coupling between antiferromagnetism and ferroelectricity in the BiFeO3 film that leads to electric-field control of the antiferromagnetic order. The second is based on exchange interactions at the interface between a ferromagnet and the antiferromagnet. This is an important step towards controlling magnetization with electric fields at different temperature, which may enable a new class of electrically controllable spintronic devices and provide a new basis

英文关键词： multiferroic properties；BiFeO3；Fe-N ferromagnetic layer；heterostructures；exchange bias at room-temperature