High coercivity in Co-Cr films induced by nitrogen gas addition during room temperature sputter-deposition

Nitrogen gas addition was investigated for deposition of Co-Cr films at room temperature. It was found that nitrogen addition has a remarkable effect on increasing perpendicular coercivity Hc_⊥ for films deposited at high Ar pressures although negligible amount of nitrogen was observed in the films. The increase in He, was interpreted in terms of a microstructure change which is characterized by development of an isolated structure accompanied by grain size reduction. Films deposited at low Ar pressures exhibited only little increase in He, with the nitrogen gas addition. Also, nitrogen inclusion and a lattice expansion were observed for these films