MAGNETORESISTIVE READ TRANSDUCER AND A METHOD FOR MAKING IT

摘要

A magnetoresistive (MR) read transducer comprising an antiferromagnetic layer (14) in direct contact with an MR layer (12) is subjected to a thermal annealing process so that a ternary antiferromagnetic alloy is formed at the interface by diffusion. The ternary antiferromagnetic alloy has a high value of exchange bias which is less temperature sensitive. In a specific embodiment in which the MR layer is NiFe and the antiferromagnetic layer is FeMn, the ternary alloy formed by heating the structure to a temperature within the range of 260 DEG C to 350 DEG C for 50 to 20 hours has a room temperature exchange bias field with NiFe of about 0.65 Amp/metre (50 Oersted) and an ordering temperature which exceeds 300 DEG C.