Patent ID: 7994597

Claim:
A method to store magnetically encoded information in a magneto-resistive memory element (MR) that includes a non-magnetic layer on a reference layer, comprising: depositing, on said non-magnetic layer, a normal free layer (NF) having a first Curie temperature; depositing, on said NF, a coupling valve layer (CV), comprising ferromagnetic material having a second Curie temperature; depositing on said CV an antiferromagnetic layer (AFM), having a blocking temperature, said second Curie temperature being less than both said first Curie temperature and said blocking temperature; then, by passing an electric current through said MR, heating said CV to a temperature that is above said second Curie temperature, and below both said first Curie temperature and said blocking temperature, whereby said CV ceases to be ferromagnetic, thereby ceasing to provide exchange coupling between said AFM and said NF through said CV; while said CV is at said temperature, magnetizing said NF in a direction that lies along said NF's easy axis, thereby storing a 1 or a 0; and then allowing said CV to cool below said second Curie temperature whereby said AFM magnetically pins said NF in said direction through exchange coupling provided by said CV.