Patent ID: 8211557

Claim:
A magnetic structure comprising: a magnetic storage layer having a magnetic easy axis perpendicular to a film plane of the magnetic layer; a magnetic assist layer having a magnetic easy axis in the film plane, wherein the magnetic assist layer has a thickness of 5 nm to 20 nm; and a temperature-dependent, exchange-coupling, phase transition interlayer between the magnetic storage layer and the magnetic assist layer, wherein the phase transition interlayer comprises Fe x Rh y , wherein x+y=97 to 100 and y=49 to 52, which exhibits a first order phase transformation from an antiferromagnetic phase to a ferromagnetic phase at a transition temperature that is greater than ambient upon heating of the phase transition interlayer to the transition temperature, and wherein the phase transition interlayer magnetically exchange couples magnetic moments of the magnetic storage layer and the magnetic assist layer when the phase transition interlayer is in the ferromagnetic phase, and wherein the exchange coupling of the magnetic storage layer and the magnetic assist layer by the phase transition interlayer is greater when the phase transition interlayer is in the ferromagnetic phase than when in the antiferromagnetic phase, wherein the magnetic structure has a characteristic that a strength of an external magnetic field required to reverse the magnetic easy axis of the magnetic storage layer is less when the phase transition interlayer is in the ferromagnetic phase than when the phase transition interlayer is in the antiferromagnetic phase.