Annealing of spin valves with high exchange pinning fields

Practical spin valves for ultra-high density recording heads require pinning fields in excess of 250 Oe to resist demagnetizing effects. One approach to achieving such high fields is through extremely thin pinned layers. Unfortunately, the thin layers of magnetic material are susceptible to annealing effects arising from the moderate temperatures at which spin valves are processed into heads. This is evidenced by a drift in pinning field. By subjecting spin valves to a short term, high temperature anneal before prolonged storage at 60/spl deg/C, subsequent drift in pinning field is suppressed,.