Structure and Magnetic Properties of FePt/Au Multilayer Film

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.