Patent ID: 6285528
Filing Date: 2001-09-04
Classification: G11B

Abstract:
A thin-film magnetic head comprising a ring-shaped magnetic core and a coil surrounded by said magnetic core, said magnetic core forming part of a magnetic path, given that an inner circumferential length of said magnetic core surrounding said coil is Lc, a magnetic gap length is g, a magnetic gap depth is D, an average magnetic flux density (unit: T (tesla)) is Bav and an effective magnetic permeability of said magnetic core is .mu., wherein Lc, g and D are determined such that a magnetomotive force I needed for recording, expressed by a following equation (1), is in a range of 0.001 A.multidot.T to 0.1 A.multidot.T. (Ampere.multidot.Turn): ##EQU20##wherein Log is a natural logarithm, and variables in said equation (1) are expressed in SI units; andwherein said magnetic core comprises a first magnetic layer formed on a head substrate side and a second magnetic layer formed on said first magnetic layer, with a thin film or a multi-layered thin film provided in a part of said magnetic path, which cuts said magnetic path and is an interface between said first magnetic layer and said second magnetic layer exclusive of the magnetic gap, said thin film or multi-layered thin film being made of at least one type of magnetic or non-magnetic material selected from the group of a non-magnetic material, a magnetic material having a lower saturation magnetic flux density than that of said magnetic core, and an antiferromagnetic material.