Fabrication of 16 nm Thick Granular L1₀ FePt-hBN Thin Film Media

Hexagonal boron nitride (hBN) has recently been investigated as a promising grain boundary material (GBM) for the nanogranular structure of L1(0)-FePt-based heat-assisted magnetic recording (HAMR) media. In this study, we systematically investigated FePt-hBN granular thin films (7.5 nm) with various hBN concentrations to provide a fundamental understanding of the effect of introducing hBN nanosheets in the medium film on its microstructure and magnetic properties. Following the optimization of the hBN concentrations, we demonstrated a method to fabricate a thicker recording layer while maintaining the desired nanogranular microstructure. We successfully fabricated the 16 nm thick FePt-hBN film with well-isolated columnar grains of diameter 6.4 nm, grain aspect ratio 2.5, and decent magnetic properties (H-C perpendicular to = 21.3 kOe and H-C// = 5 kOe).