Nd – Fe – B films with perpendicular magnetic anisotropy

Abstract

The dependence of magnetic properties on the film thickness has been studied for Nd–Fe–B films with perpendicular magnetic anisotropy. The W underlayer was used for preventing oxidation of Nd. It is found that the perpendicular coercivity decreases with the increase of the film thickness, although the thick film still has perpendicular magnetic anisotropy. A laminated structure composed of [Nd–Fe–B∕W]n has been proposed to prepare thick Nd–Fe–B with higher coercivity. The laminated structure can suppress the grain growth in Nd–Fe–B films while still keeping the perpendicular anisotropy.