Abstract: A tunnel magnetoresistance effect magnetic head having between magnetic shield layers, an antiferromagnetic layer, a pinned layer which has the direction of magnetization pinned by exchange coupling with the antiferromagnetic layer, an insulating layer, and a free layer whose direction of magnetization rotates relatively to external magnetic fields, wherein the antiferromagnetic layer is of an antiferromagnetic substance composed mainly of IrMn, the pinned layer is made up of a first pinned layer of CoFe alloy in contact with the antiferromagnetic layer and a second pinned layer of CoFeB alloy which is antiferromagnetically coupled with the first pinned layer, and the first and second pinned layers have the amount of magnetization such that the difference M1?M2 is in the range of 0<M2?M1<0.5 (nm·T) and also have the magnetostriction constants such that the difference |?1??2| is no larger than 5.0×10?6.

Abstract: Embodiments of the present invention prevent a pinned layer from suffering magnetization reversal by external stress in a magnetic head of magnetoresistance effect type which has a synthetic ferri-magnetic pinned layer structure with an antiferromagnetic layer of IrMnCr. According to one embodiment, a read element of a magnetoresistive head is made up of a antiferromagnetic layer, a first pinned layer, an antiferromagnetically coupled layer 4, a second pinned layer, and a free layer, which are stacked one over another. The first and second pinned layers and have a composition of Co75Fe25 and Co95Fe5, respectively, and a thickness of 18 ? (3.5 nm·T) and 21 ? (3.9 nm·T), respectively, so as to reduce the difference in anisotropic energy between the first pinned layer in contact with the antiferromagnetic layer and the second pinned layer in contact with the nonmagnetic conductive layer.