Patent ID: 7567412

Claim:
A magnetic sensing element comprising a multilayer film including a pinned magnetic layer whose magnetization direction is pinned in one direction and a free magnetic layer formed on the pinned magnetic layer with a nonmagnetic material layer disposed therebetween, the free magnetic layer including a low-coercivity layer and an enhancement layer comprising a material having a higher spin-dependent scattering coefficient than the material for the low-coercivity layer, the enhancement layer being disposed closer to the nonmagnetic material layer than the low-coercivity layer, the enhancement layer including a first enhancement layer and a second enhancement layer, the first enhancement layer being disposed closer to the nonmagnetic material layer than the second enhancement layer, the overall enhancement layer having a lower magnetostriction coefficient λ in absolute value than the first enhancement layer, wherein the first enhancement layer comprises Co or a CoFe-containing alloy, and the second enhancement layer comprises a CoFe-containing alloy having a lower Co content than the material for the first enhancement layer, the first enhancement layer comprises a Co x Fe 100-x alloy (wherein 90≦x≦100 in atomic percent), and the second enhancement layer comprises a Co y Fe 100-y alloy (wherein 70≦y≦88 in atomic percent) and the overall free magnetic layer has a magnetostriction coefficient λof 0 to 5 ppm.