Comparative Studies on the Microstructure and Magnetic Properties of FePt/ (Ag, MgO) Nanocomposite thin Films on Glass Substrate

A comparative study on the microstructure and magnetic properties of FePt-MgO and FePt-Ag thin film sputtered onto glass substrate has been carried out systematically in this paper. FePt-MgO thin film shows better (001) orientation of L10-ordered FePt phase, narrower c-axis orientation distribution, higher out-of-plane coercivity, higher remanence ratio and larger hysteresis slope α than the FePt-Ag thin film. The results of angular variation of coercivity indicate that the magnetization reversal behavior of FePt-MgO thin film is closer to the Stoner–Wohlfarth rotation model than that of FePt-Ag thin film. The magnetic domain size in FePt-MgO thin film (∼80nm) is smaller than that in FePt-Ag thin film (∼160nm) due to the isolated grain structure. From this point of view, the FePt-MgO thin film is more suitable than the FePt-Ag thin film for the application of high density recording media.