R&D: Fabrication of 16nm-Thick Granular L10 FePt-hBN Thin Film Media

IEEE Transactions on Magnetics has published an article written by Chengchao Xu, B.S.D.Ch.S. Varaprasad, Data Storage Systems Center, Carnegie Mellon University, Pittsburgh, PA, USA, and Electrical and Computer Engineering Department, Carnegie Mellon University, Pittsburgh, PA, USA, David E. Laughlin, Data Storage Systems Center, Carnegie Mellon University, Pittsburgh, PA, USA, and Electrical and Computer Engineering Department, Carnegie Mellon University, Pittsburgh, PA, USA, and Materials Science and Engineering Department, Carnegie Mellon University, Pittsburgh, PA, USA, and Jian-Gang Zhu, Data Storage Systems Center, Carnegie Mellon University, Pittsburgh, PA, USA, Electrical and Computer Engineering Department, Carnegie Mellon University, Pittsburgh, PA, USA, and Materials Science and Engineering Department, Carnegie Mellon University, Pittsburgh, PA, USA.

Abstract: “Hexagonal boron nitride ( h BN) has recently been investigated as a promising grain boundary material for the nanogranular structure of L1 ₀ -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 16nm-thick FePt- h BN film with well-isolated columnar grains of diameter 6.4nm, grain aspect ratio 2.5, and decent magnetic properties ( H _C⊥ =21.3 kOe, H _C// =5 kOe).“