Structure, magnetic and thermal properties of FePt–C–BN granular films for heat assisted magnetic recording

Abstract

Abstract The structure, magnetic and thermal properties of (FePt0.78–C0.22)–BN granular films with various BN volume concentrations are systematically studied. Compared to the FePt–C film without BN doping, the grain size distribution of the FePt grains is reduced by 50% with BN component is 10 vol.%, and the coercivity and the intrinsic switching field distributions of the film are increased 3 times and narrowed by 35%, respectively, when BN component is 6 vol.%. The improvement in magnetic properties is attributed to the enhanced chemical ordering of the FePt L10 phase. Based on the 3ω method, it is found that the relative cross-plane thermal conductivity of the FePt–C–BN layer is more correlated to the grain size distribution of the film, which decreases to the minimum value at 10 vol.% BN. Our results indicate that a certain amount of BN doping can improve the comprehensive performance of the FePt–C–BN granular films, making it a promising candidate for heat assisted magnetic recording.