FePt薄膜中磁相互作用

采用磁控溅射方法在自然氧化的单晶Si(100)衬底上制备了纳米结构的Fe₅₃Pt₄₇薄膜，并研究热处理后薄膜中的磁相互作用、晶粒尺寸与热处理温度的关系.经400℃热处理后，FePt薄膜中有明显的面心四方相形成，薄膜表现出硬磁性，晶粒尺度在20 nm，薄膜内部存在软硬磁交换耦合作用；随着热处理温度升高，硬磁相含量增加.同时由于FePt薄膜的晶粒长大，部分软硬磁晶粒之间的交换耦合作用失效；600℃热处理后，FePt的面心立方相已经完全转变为面心四方相，薄膜矫顽力由硬磁相之间的静磁作用贡献. 关键词： 磁性薄膜 纳米晶 磁性能 热处理

The magnetic interactions in FePt nanocomposite film

Fe₅₃Pt₄₇ nanocomposite films have been deposited on naturally oxidized Si(100) substrates by magnetron sputtering. The relationship between the grain size, the magnetic interaction and the annealing temperature have been studied. The FePt films exhibit magnetically hard property with average grain size of about 20 nm after annealing at 400℃, and exchange spring behavior was found in the sample because it is composed of magnetically soft γ-FePt phase and hard γ₂-FePt phase. As the annealing temperature increases, the content of the γ₂-FePt phase increases, at the same time, the grain size gets large, and the exchange spring behavior in some particles was discoupled. The static magnetic interaction only occur between the FePt particles in the film annealed at 600℃.