Patent ID: 7466526

Claim:
A ferromagnetic tunnel junction, comprising: a pinned magnetic layer; a tunnel insulating film formed on the pinned magnetic layer; and a free magnetic multilayer body formed on the tunnel insulating film; wherein the free magnetic multilayer body includes a first free magnetic layer, a diffusion barrier layer, and a second free magnetic layer stacked in this order on the tunnel insulating film, the first free magnetic layer and the second free magnetic layer being ferromagnetically coupled with each other, a magnetization direction of the first free magnetic layer and a magnetization direction of the second free magnetic layers being parallel to each other, the first free magnetic layer containing CoFe and at least one additive element selected from the group consisting of B, C, Al, Si, Zr, and P; and the diffusion barrier layer being formed of any one of the elements selected from the group consisting of Ta, Ti and Hf, the diffusion barrier layer inhibiting the additive element contained in the first free magnetic layer from diffusing into the second free magnetic layer.