FePt/Au多层膜的结构和磁性能研究

Structure and Magnetic Properties of FePt/Au Multilayer Film

摘要:

采用磁控溅射在SiO2<0001>基片上制备了FePt(2 nm)/Au(t nm)多层膜，将其在不同温度下进行热处理。利用X射线荧光光谱仪、X射线衍射仪、振动样品磁强计和原子力显微镜对样品的结构和性能进行了研究。结果表明，沉积态样品具有超晶格结构，fcc FePt和Au共格生长。经过较低温度热处理后，样品仍然保持超晶格结构。样品经400 ℃热处理后，开始发生有序化转变。经600 ℃热处理后，平行于膜面和垂直于膜面的矫顽力分别为811.7和829.2 kA·m-1。当t=2.5 nm时，最有利于L10-FePt相的形成。在磁化过程中，畴壁移动和磁矩转动机制共存。样品经热处理后，形成了均匀的薄膜。

Abstract:

The FePt(2 nm)/Au(t nm) multilayer films were deposited on SiO2<0001> substrates by magnetron sputtering system at room temperature, and then the as-deposited films were annealed at various temperatures. The structure and properties of the films were investigated by X-ray fluorescence spectrometer, X-ray diffraction, the vibrating sample magnetometer and atomic force microscopy. The results indicate the as-deposited FePt/Au multilayer films show a superlattice structure for the coherent growth between fcc FePt and Au. And the films annealed at a lower temperature are still of superlattice structure. The transformation in FePt film from disorder to order phase takes place when the films are annealed at 400 oC. After annealing at 600 oC, the in-plane and out-of-plane coercivity of the film is 811.7 and 829.2 kA·m-1, respectively. It is optimal to form the L10-FePt when the Au layer thickness is 2.5 nm. Domain wall motion and moment rotation exist in the magnetizing process at the same time for all the films. Uniform films are formed for the samples after annealing.