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

Hexagonal boron nitride (
${h}$
BN) has recently been investigated as a promising grain boundary material (GBM) for the nanogranular structure of L10-FePt-based heat-assisted magnetic recording (HAMR) media. In this study, we systematically investigated FePt-
${h}$
BN granular thin films (7.5 nm) with various
${h}$
BN concentrations to provide a fundamental understanding of the effect of introducing
${h}$
BN nanosheets in the medium film on its microstructure and magnetic properties. Following the optimization of the
${h}$
BN 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-
${h}$
BN film with well-isolated columnar grains of diameter 6.4 nm, grain aspect ratio 2.5, and decent magnetic properties (
${H} _{\mathbf {C\bot }}$
= 21.3 kOe and
${H} _{\mathbf {C//}}$
= 5 kOe).