Permeability dependence of thin film head reproducing performance

Permeability of Ni-Fe thin film head yokes and its effect on the head sensitivity were studied by simulations and experiments. Examinations focused on head inductance with closed magnetic paths and reproducing performance. The reproduced output signal amplitude resulted from simulations had a larger permeability dependence around the pole tip than any other areas. The output was reduced approximately 2 % when the permeability around the tip was lowered from 3000 to 300. This permeability was estimated at between 50 and 300 in fabricated heads, while it was approximately 1000 elsewhere.