Characterization of magnetic and thermal stability of PtMn spin valves

A PtMn pinned top spin valve was made by DC sputtering with good GMR proper ties. GMR ratio of 14.7% and dR of 2.4 ohms/sq, were obtained for the optim um process, The pinning reversal process is a function of time, temperature , and applied field. For a typical spin valve the pining field reverses aro und 300 degreesC under a field of 1000 Oe which is sufficient for the head application, Furthermore, the PtMn antiferromagnetic (AFM) layer can be mad e into a thin layer of 100 Angstrom with a relatively high blocking tempera ture of 380 degreesC. Between room temperature and 200 degrees C, the GMR r esponses are highly reversible for both sheet films and finished PtMn spin valve heads.