Patent ID: 7502210

Claim:
A magnetic detecting device comprising: a multilayer film, which has at least one pinned magnetic layer magnetized in one direction and a free magnetic layer formed on the pinned magnetic layer with a nonmagnetic material layer therebetween, and in which a sense current flows in the direction perpendicular to the plane of each layer forming the multilayer film, wherein the free magnetic layer includes a Ni a Fe b alloy layer (a and b are represented by at %, and satisfy the relationship of 47≦a≦77 and a+b=100), the pinned magnetic layer includes a Co 2 YZ alloy layer (Y is one or more elements of Mn, Fe, and Cr, and Z is one or more elements of Al, Ga, Si, Ge, Sn, In, Sb, Pb, and Zn), and wherein the Co 2 YZ alloy has a Heusler structure.