Magnetic Properties and Domain Observations for CoZr/NiFe Multilayer Films

The magnetic properties and domain structures of amorphous Co90Zr10/ polycrystalline Ni81Fe19 (wt%) multilayer films, candidates for use as the pole pieces of thin-film heads, were investigated. After sputter-forming film samples in a 400 Oe magnetic field, they were annealed with a 480 Oe field either in the easy axis and then the hard axis directions, or rotating relative to the sample. The latter type of annealing resulted in increased permeability and a weakened anisotropy field. Observations of domain structures indicated that the multilayer films have stable and reproducible domains in both magnetized and demagnetized states.