铁酸铋/铁磁薄膜体系的交换偏置与可逆电控磁效应的研究

项目名称： 铁酸铋/铁磁薄膜体系的交换偏置与可逆电控磁效应的研究

项目编号： No.51471085

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 杜军

作者单位： 南京大学

项目金额： 85万元

中文摘要： 多铁性材料将磁有序和电有序等多种铁性集中在一起，可实现多种铁性间的相互调控。BiFeO3是少有的室温多铁性材料（铁电性和反铁磁性），其在自旋电子学中最有效的应用是作为反铁磁钉扎层。我们可利用铁磁/反铁磁薄膜体系的交换偏置效应以及多铁性材料的磁电耦合效应，实现电场对被钉扎的铁磁层磁性的调控。在本项目中我们将着重研究以下三方面的内容：1）以BiFeO3作为反铁磁层，以NiFe等铁磁金属或NiFe2O4等铁磁氧化物作为铁磁层，制备反铁磁/铁磁双层膜，系统地研究其交换偏置效应的物理机制；2）系统地研究外加电场对影响BiFeO3/铁磁界面交换偏置效应的各因素的调控机制，通过改变BiFeO3的晶体结构、铁电畴结构和自旋结构，实现外加电场对被钉扎的铁磁层磁性的可逆调控；3）将BiFeO3/铁磁结构应用于磁性隧道结或自旋阀中，实现电场对磁电阻效应的可逆调控，为研制电场调控的新型自旋电子器件奠定基础。

中文关键词： 交换偏置；多铁性材料；磁性薄膜；自旋电子学

英文摘要： Multiferroic materials combine the ferroics (mainly magnetic and ferroelectric orderings) in one material, providing the multiple control of the two or more ferroics. BiFeO3 is the very rare room-temperature multiferroic material (ferroelectricity,antiferromagnetism), and its most plausible application in spintronics is the antiferromagnetic pinning layer. The magnetic properties of the pinned ferromagnetic layer can be manipulated by the electric field applied on BiFeO3 through the exchange bias effect in ferromagnetic/antiferromagnetic bilayers and the magnetoelectric coupling effect in multiferroic materials. In this project, we will mainly focus our research on the following aspects: 1) We will fabricate the antiferromagnetic/ferromagnetic bilayers using BiFeO3 as antiferromagnetic layer, ferromagnetic metal (NiFe, etc.) or ferromagnetic oxide (NiFe2O4, etc.) as ferromagnetic layer, and systematically study the mechanism of the exchange bias effect; 2) We will systematically study the controlling mechanism of the applied electric field on each factor which influences the exchange bias at the BiFeO3/ferromagnetic interface. With the control of crystal structure, ferroelectric domain structure and spin structure of BiFeO3, we will try to realize the reversible manipulation of the magnetic properties of the pinned ferromagnetic layer by the electric field; 3) We will apply BiFeO3/ferromagnetic bilayer in magentic tunnel junctions or spin valves, and try to realize the reversible electrical manipulation of the magnetoresistance, which will lay the foundation of devloping new type electric-field-tunable spintronic devices.

英文关键词： exchange bias;multiferroic material;magnetic films;spintronics