Crystal structure and magnetic properties of Permalloy films sputtered by mixed Ar-N2 gases

The crystallographic and magnetic properties of 1-μm-thick Permalloy films sputtered by mixed argon and nitrogen gases have been investigated. These films are composed of (111) textured grains of face-centered cubic and (002) textured grains of body-centered tetragonal which are deformed from face-centered cubic. Adding nitrogen to argon gas increases the amount of (002) textured grains and lattice strain. The anisotropy field of these films is smaller than that of films sputtered by pure argon. The coercive force of films containing relatively large amounts of nitrogen increases with annealing. The coercive force of the annealed films is correlated with a change in the lattice constant of the face-centered cubic grains. The magnetocrystalline anisotropy of these grains is likely to be one of the causes of perpendicular anisotropy