Patent ID: 6690163
Filing Date: 2004-02-10
Classification: B82Y,G01R,G11B,Y10T

Abstract:
A magnetic sensor comprising a spin-valve film or tunnel junction film having a layered structure of a soft magnetic free layer, a nonmagnetic intermediate layer, and a ferromagnetic pinned layer,wherein the magnetization of the ferromagnetic pinned layer is pinned with respect to a magnetic field to be sensed, the magnetization of the soft magnetic free layer rotates according to an external magnetic field, and a relative angle between the magnetization of the soft magnetic free layer and the magnetization of the ferromagnetic pinned layer is changed, thereby causing magnetoresistance, the soft magnetic free layer has a structure of an Ni alloy layer, an interface control layer, and a Co alloy layer, the Ni alloy layer is made of 70 to 90 at % of nickel and the balance of iron, or 0.1 to 20 at % of cobalt and, in the balance, 70 to 90% of nickel and 10 to 30% of iron, the Co alloy layer is made of pure Co, 50 to 99 at % of cobalt and the balance of iron, or 40 to 99 at % of cobalt, 1 to 30 at % of nickel, and 1 to 30% of iron, and the interface control layer is made of Cu, Au, Ru, Ag, Pt, Pd, Ir, Rh, Re, Os, or an alloy of any of them and has a thickness of 1 nanometer or less.