Fabrication of FePt/FePt-BN/FePt-SiO_x Granular Film for HAMR Media on Corning Lotus NXT Glass Substrate

In this article, we present the fabrication of FePt/FePt-BN/FePt-SiO _x and conventional FePt/FePt-C for heat-assisted magnetic recording (HAMR) on Corning Lotus NXT glass substrates. For FePt/FePt-BN/FePt-SiO _x media, a 2.5 nm FePt/FePt-35vol.%BN was fabricated on polycrystalline MgO underlayers at 700 °C to serve as the templated layer for the growth of 4 nm FePt-35vol.%SiO _x at 550 °C. For the FePt/FePt-C media, 6.5 nm FePt/FePt-C media was fabricated at 550 °C with FePt and C co-sputtered on top of 0.5 nm FePt. Both media show well-isolated FePt grains, which are fully surrounded by the grain boundaries materials. Compared with FePt/FePt-C media, the FePt/FePt-BN/FePt-SiO _x media show distinctively smaller grain-to-grain pitch distance or higher grain areal density. Moreover, the bimodal grain-size distribution that is often observed in FePt/FePt-C media has been suppressed in the FePt/FePt-BN/FePt-SiO _x media. In addition, both media show good magnetic properties on Corning Lotus NXT glass substrate.