Patent ID: 7733612

Claim:
A giant magneto-resistive effect device (GMR device) having a CPP (current perpendicular to plane) structure comprising a nonmagnetic spacer layer, and a fixed magnetized layer and a free layer stacked one upon another with said nonmagnetic spacer layer interleaved between them, with a sense current applied in a stacking direction, characterized in that: said free layer functions such that a direction of magnetization changes depending on an external magnetic field, and said fixed magnetization layer has a synthetic pinned morphology wherein an inner pin layer and an outer pin layer are stacked one upon another with a nonmagnetic intermediate layer held between them, said inner pin layer being located at a position nearer to said nonmagnetic spacer layer than to said outer pin layer, wherein: a width W 1 of said inner pin layer at a position tangent to said nonmagnetic spacer layer as viewed from a medium opposite plane is set at 50 nm or less, said fixed magnetization layer has tapers at both ends as viewed from a medium opposite plane, each of said tapers is tapered down to said non-magnetic spacer layer with the stacking direction of said device as a center axis direction, wherein a taper angle θ 1 with respect to a reference line defined by a stacking plane as viewed from a medium opposite plane side is set in an angle range of 40° to 60°, a magnetic volume ratio (Mso×V 2 )/(Msi×V 1 ), represented by a ratio of (Mso×V 2 ) that is a product of a saturation magnetization Mso and a volume V 2 of said outer pin layer relative to (Msi×V 1 ) that is a product of a saturation magnetization Msi and a volume V 1 of said inner pin layer, lies in a range of 0.9 to 1.1, and a magnetic thickness ratio (Mso×t 2 )/(Msi×t 1 ), represented by a ratio of (Mso×t 2 ) that is a product of a saturation magnetization Mso and a thickness t 2 of said outer pin layer relative to (Msi×t 1 ) that is a product of a saturation magnetization Msi and a thickness t 1 of said inner pin layer, is set at 0.8 or less.