Patent ID: 7372116

Claim:
A magnetic memory cell for use in a magnetic random access memory array, the memory cell comprising: a first magnetic layer structure having a magnetization; a second magnetic layer structure having a magnetization; and a barrier layer sandwiched between said first and second magnetic layer structures; a first layer of antiferromagnetic material having a first blocking temperature exchange coupled with the first magnetic layer structure such that the first layer of antiferromagnetic material pins the magnetization of the first magnetic layer structure; and a second layer of antiferromagnetic material comprising FeRh having a second blocking temperature lower than the first blocking temperature exchange coupled with the second magnetic layer structure such that the second layer of antiferromagnetic material pins the magnetization of the second magnetic layer structure when the memory cell is below the second blocking temperature and leaves the second magnetic layer structure free to move in response to the memory cell is raised to a temperature between the first and second blocking temperatures; wherein said second magnetic layer includes a first sub-layer formed adjacent to the FeRh layer and a second sub-layer formed adjacent to the barrier layer, the first sub-layer comprising a material selected from the group consisting of FePt, CoPt, FePd, and CoPd, the second sub-layer comprising a material selected from the group consisting of Co, Fe, Ni and their alloys.