Rotatable Anisotropy in Composite Films

The anisotropy in the plane of the film of thin films of Ni evaporated on Mo-covered substrates and of oxidized Ni films has been measured as a function of field and temperature. At intermediate fields, 200–1200 oe, a large rotatable anisotropy is found, about an order of magnitude larger than the usual magnetic annealing anisotropy. At higher fields the rotatable anisotropy disappears and only the magnetic annealing anisotropy remains. The temperature dependence of the rotatable anisotropy indicates a connection with the antiferromagnetic character of NiO.