Control of the microstructure of FePt-SiNx -C (001) film by a nucleation layer grown on TiN intermediate layer

Abstract

The microstructure and magnetic properties of granular FePt-SiN x-C films were modified by introducing an MgO nucleation layer grown on the TiN intermediate layer. It was found that the deposition of an ultra-thin MgO nucleation layer could reduce the FePt grain size, narrow grain size distribution and improve grain isolation by creating more nucleation sites. When MgO nucleation layer thickness varied from 0 to 0.36 nm, FePt grain size was reduced from 8.51 nm to 7.18 nm and the standard deviation of the grain size distribution was narrowed from 2.16 nm to 1.51 nm. Good L10 (001) texture was maintained and large out-of-plane coercivity (27.5 kOe) was obtained at the MgO thickness of 0.36 nm. Meanwhile, Δθ50 of FePt (001) peak decreased from 7.1° to 6.4°, indicating the improved easy axis distribution of FePt grains. However, with the further increase of the MgO nucleation layer thickness, MgO nuclei developed into a continuous layer, FePt (111) orientation appeared and the perpendicular magnetic anisotropy was deteriorated. © 2013 IEEE.