Patent ID: 7271698

Claim:
A laminated ferrimagnetic thin film, comprising: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic intermediate layer which is arranged therebetween and in contact with the first ferromagnetic layer and the second ferromagnetic layer, the first ferromagnetic layer and the second ferromagnetic layer being magnetically coupled with each other through the non-magnetic intermediate layer in an anti-ferromagnetic manner, wherein the first ferromagnetic layer comprises a first main ferromagnetic layer comprising at least one layer, and a first interface ferromagnetic layer which is arranged between and in contact with the first main ferromagnetic layer and the non-magnetic intermediate layer, wherein the second ferromagnetic layer comprises a second main ferromagnetic layer comprising at least one layer, and a second interface ferromagnetic layer which is arranged between and in contact with the second main ferromagnetic layer and the non-magnetic intermediate layer, wherein each of the first interface ferromagnetic layer and the second interface ferromagnetic layer comprises at least one of Co and a Co alloy, wherein each of at least one layer in the first main ferromagnetic layer and at least one layer in the second main ferromagnetic layer comprises a soft magnetic layer having a coercive force smaller than that of each of the first interface ferromagnetic layer and the second interface ferromagnetic layer, wherein a total film thickness of layers comprising the soft magnetic layers in the first main ferromagnetic layer comprises not less than 60% of a film thickness of the first ferromagnetic layer, wherein a total film thickness of layers comprising the soft magnetic layers in the second main ferromagnetic layer comprises not less than 60% of a film thickness of the second ferromagnetic layer, wherein said laminated ferrimagnetic thin film is a free layer in a magneto-resistive effect element, and wherein the Co alloy comprises a Co x Fe 1-x alloy, where 0.75≦X<1.