Patent ID: 6714380
Filing Date: 2004-03-30
Classification: G11B,H01F,Y10T

Abstract:
A thin-film magnetic head comprising a lower core layer, an upper core layer, and a magnetic pole portion provided between the lower core layer and the upper core layer, a width in a track width direction of the magnetic pole portion being formed smaller than that of each of the lower core layer and the upper core layer,wherein the magnetic pole portion comprises a lower magnetic pole layer in contact with the lower core layer, an upper magnetic pole layer in contact with the upper core layer, and a gap layer provided between the lower magnetic pole layer and the upper magnetic pole layer, at least one of the upper magnetic pole layer and the lower magnetic pole layer contains at least two sub-magnetic layers, in which a sub-magnetic layer in contact with the gap layer has a composition represented by CoxFeyNiz, wherein X is 8 to 48 mass %, ratio Y is 50 to 90 mass %, ratio Z is 2 to 20 mass %, X+Y+Z being 100 mass %, and at least one sub-magnetic layer other than the sub-magnetic layer in contact with the gap layer is formed of an NiFe alloy.