Patent ID: 8778515

Claim:
A magneto-resistive effect element comprising: a first pinned ferromagnetic layer including a first ferromagnetic film having a magnetization direction fixed in one direction; an antiparallel coupling (APC) layer positioned above the first pinned ferromagnetic layer, the APC layer comprising Ru; a first interface magnetic layer positioned at an upper interface of the APC layer; a second pinned ferromagnetic layer positioned above the first interface magnetic layer, the second pinned ferromagnetic layer including a second ferromagnetic film having a magnetization direction fixed in one direction; a second interface magnetic layer positioned at an upper interface of the second pinned ferromagnetic layer; a current confinement layer positioned above the second interface magnetic layer, the current confinement layer being configured to confine a current and consisting of a nonmagnetic conductive metal and an insulating material; a free ferromagnetic layer positioned above the current confinement layer, the free ferromagnetic layer including a third ferromagnetic film having a magnetization direction varying in response to an external magnetic field; and an intermediate layer positioned between the second pinned ferromagnetic layer and the free ferromagnetic layer; and a third interface magnetic layer positioned at a lower interface of the free ferromagnetic layer, wherein at least one of the second pinned ferromagnetic layer and the free ferromagnetic layer comprise a highly spin polarized layer, and wherein at least one of said second interface magnetic layer or third interface magnetic layer is a metallic alloy having at least one of Fe, Co and Ni.