Effect of CoPtCr/Cr on the magnetic properties of Permalloy

The effect of a hard bias material, CoCrPt, on the magnetic properties of Permalloy has been studied as a function of spacer layer thickness. In particular, a large increase in the coercivity without reduction in squareness of NiFe is observed. This increase may have relevant implications in the design of magnetoresistive heads. The results are explained qualitatively using a Random Field approach in the Imry-Ma.