外延铁氧化物薄膜及其异质结构的磁输运各向异性研究

项目名称： 外延铁氧化物薄膜及其异质结构的磁输运各向异性研究

项目编号： No.11204207

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 李鹏

作者单位： 天津大学

项目金额： 28万元

中文摘要： 各向异性磁电阻和隧穿型各向异性磁电阻在磁性传感器和磁存储方面具有潜在的应用价值。与传统非晶和多晶体系中存在的两重轴对称各向异性磁电阻不同，最近在诸多体系中观察到的四重轴对称各向异性磁电阻随磁场的增大而增大且不饱和。存在四重轴对称各向异性磁电阻的钙钛矿锰氧化物、磁性半导体以及四氧化三铁的载流子均是自旋极化的，铜氧化物高温超导体和外延四氧化三铁薄膜中均存在反铁磁耦合。隧穿型各向异性磁电阻与铁磁绝缘层磁各向异性的关系并不清晰。本课题拟使用反应溅射的方法制备外延铁氧化物四氧化三铁和伽马-三氧化二铁薄膜及其异质结构，重点研究四氧化三铁薄膜中高对称性各向异性磁电阻与自旋极化率和反铁磁耦合之间的关系，以及伽马-三氧化二铁基异质结构的隧穿型各向异性磁电阻与磁各向异性之间的关系。该研究结果将为高对称性各向异性磁电阻的解释积累经验，弄清楚隧穿型各向异性磁电阻与势垒层磁各向异性之间关系。

中文关键词： 各向异性磁电阻；平面霍尔效应；半金属；异质结构；

英文摘要： In Spintronics, anisotropic magnetoresistance (AMR) and tunneling anisotropic magnetoresistance (TAMR) is promising in magnetic sensors and magnetic storages. Compared to the two-fold symmetric AMR in traditional amorphous and polycrystalline magnetic materials, four-fold symmetric AMR has been observed in several epitaxial films, including perovskite manganites, magnetic semiconductors, high-TC cuprates and half-metallic Fe3O4. Contrary to the traditional anisotropic magnetoresistance, the AMR with high symmetry increases with the increasing magnetic fields and is unsaturated although the magnetic field is larger than the anisotropic field. The carriers in perovskite manganites, magnetic semiconductors and Fe3O4 are spin-polarized, and the antiferromagnetic coupling exists in high-TC cuprates and epitaxial Fe3O4 films. The relationship between the TAMR and the magnetic anisotropy of ferromagnetic insulating layer is not clear. We intend to fabricate the epitaxial iron oxide, Fe3O4 and γ-Fe2O3, films and heterostructures by reactive sputtering. The investigation focuses on the relationship between the AMR with high symmetry in epitaxial Fe3O4 films and spin polarization and antiferromagnetic coupling, as well as the relation between the TAMR in epitaxial γ-Fe2O3 related heterostructures and magnetic anisotropy o

英文关键词： anisotropic magnetoresistance；planar Hall Effect；half metal；heterostructure；