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

The structure, magnetic and thermal properties of (FePt_0.78-C_0.22)-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 [ image ] 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.