Abstract
A 13 monolayer Ni film was deposited on Cu(001) and followed by oxygen exposure at 300 K. It was confirmed that the surface contained Ni oxide with an amorphous atomic arrangement. The magnetization is perpendicular after surface oxidation. The coercivity is substantially enhanced without shifting of the hysteresis loop after field cooling. This could indicate that the NiO is randomly antiferromagnetic or that the Nel temperature of the NiO is above 300 K. This surface oxide leads to surface passivation so that the film is magnetically alive under ambient conditions, which could have useful applications in the future. © 2012 American Institute of Physics.