Characterization of magnetic and thermal stability of PtMn spin valves

A PtMn pinned top spin valve was made by DC sputtering with good GMR properties. GMR ratio of 14.7% and dR of 2.4 ohms/sq. were obtained for the optimum process. The pinning reversal process is a function of time, temperature, and applied field. For a typical spin valve the pinning field reverses around 300/spl deg/C under a field of 1000 Oe which is sufficient for head application. Furthermore, the PtMn antiferromagnetic (AFM) layer can be made into a thin layer of 100 A with a relatively high blocking temperature of 380/spl deg/C. Between room temperature and 200/spl deg/C, the GMR responses are highly reversible for both sheet films and finished PtMn spin valve heads.