Two-dimensional growth of Fe thin films with perpendicular magnetic anisotropy on GaN(0001)

Abstract

The growth and magnetism of Fe thin films on the GaN(0001) surface are studied by scanning tunneling microscopy and surface magneto-optic Kerr effect. It is found that Fe grows in a layer-by-layer mode on the pseudo- 1×1 surface at room temperature, and the film develops magnetism at 1.2 ML and shows perpendicular magnetic anisotropy below 6 ML. On the bulk-terminated 1×1 surface, Fe grows in a three-dimensional mode, and ferromagnetization with in-plane anisotropy is observed only above 4.3 ML. Fe-induced √7×√7 reconstruction on the pseudo- 1×1 surface plays the key role in reducing the interface reaction and promoting the two-dimensional growth. © 2006 American Institute of Physics.