Interplay of the magnetoelastic and shape anisotropy on the evolution of magnetic domain structure of amorphous Nd–Fe–B films

Abstract

Amorphous Re–Fe–B (Re rare-earth) films are prepared on thermally oxidized Si substrates with Nb buffer layers by dc magnetron sputtering. We observed the evolution of magnetic domain structure in these films under the external magnetic field parallel to the film plane and discussed its origin. The magnetoelastic anisotropy and shape anisotropy can be adjusted by changing the deposition temperature and the thickness of the film. The results showed that the magnetic domain structure for a film with lower sputtering temperature (150°C) and thinner thickness (200nm) has changed significantly with the applied magnetic field and form stripe domains arranged along the direction of the field. However, for the film with higher sputtering temperature (300°C) and thicker thickness (600nm), magnetic domain structure is hardly varied with applied field. We suggest the evolution of magnetic domain structure is determined by the interplay of the magnetoelastic anisotropy and shape anisotropy energy, which will lead to the easy magnetization direction of amorphous Re–Fe–B films inclined to the normal direction instead of perpendicular to the film plane.