Disaccommodation of Permeability on CoZrNb Amorphous Thin Films

The deterioration of the permeability of CoZrNb amorphous films is discussed. The permeability was measured using a B-H loop tracer, and the deterioration with heat treatment or aging in ac magnetic fields. Deterioration is more pronounced in thinner films, but no deterioration was observed in samples aged in ac magnetic fields. Permeability was restored by reheating, but began to deteriorate afterward. The degree of deterioration also depends on the film composition. The results indicated that the deterioration was caused by atomic rearrangement near the film and substrate interface.