A method for switching field distribution measurement of heat assisted magnetic recording media

Due to increased emphasis on heat assisted magnetic recording, the characterization of switching field distribution (SFD) at elevated media temperatures has become important. In this paper, we introduce an efficient method to measure SFD based on optical heating and MOKE measurement. The Major and minor hysteresis loops of perpendicular magnetic recording media and FePt granular media were acquired at different optical heating powers. The optical heating power (or temperature) dependent SFD of FePt granular media was measured. We observe SFD broadening of HAMR media at elevated temperatures which is consistent with theoretical predictions.