Low temperature deposited L1 FePt–C (001) films with high coercivity and small grain size

Abstract

FePt–C films with high coercivity, (001) texture, and small grain size were deposited on MgO∕CrRu/glass substrate by cosputtering FePt and carbon at 350°C. The out-of-plane coercivity measured at room temperature increased from 9.6to15.1kOe when C concentrations increased from 0% to 15%. Further increasing the C contents to 20% and 25% caused the decrease of coercivity to 13.6 and 11.8kOe, respectively. With C doping, a two-layer structure of FePt–C films was formed and fcc-phase FePt particles were found. By optimizing the sputtering process, FePt–C (001) film with coercivity higher than 14.4kOe and columnar FePt grains of 7.5nm in diameter was obtained, which are suitable for ultrahigh density perpendicular recording.