GMR-DMR read-element characterization and projections of head performance on high areal density rigid media

In this work, the device level properties of GMR-DMR read-elements (REs) fabricated from an antiferromagnetically coupled continuous multilayer, that exhibited large giant magnetoresistance, are characterized, REs having stripe heights of 1 and 2 μm and a trackwidth of 3 μm, were characterized in terms of self stabilized single domain state, electric/magnetic homogeneity and sensitivity to spatial gradient fields. A simple two-parameter model of the interlayer coupling in the GMR multilayer film, fit to only the sheet film MR loops, was combined with micromagnetic simulations to fairly accurately predict the experimental curves obtained with the REs. Temperature effects due to Joule heating at higher sense currents were accounted for in the theoretical curves, by using measured resistance and GMR ratio variation with temperature. Projections of the performance of a GMR-DMR head that uses a similar multilayer film are presented