Micromagnetic simulation of 10 Gb/in/sup 2/ spin-valve heads

Micromagnetic modeling was used to study the behavior of a shielded, spin-valve head with dimensions appropriate for 10 Gb/in/sup 2/ recording. Signal symmetry and magnitude as a function of bias current was studied for three head geometries. The errors introduced by the common approximations of perfect pinning in the pinned layer and two-dimensional geometry are investigated. Transfer curve asymmetry was found to be greater for practical exchange pinning fields than for the perfect pinning sometimes assumed. Signal amplitudes were found to be lower than would be predicted by 2 dimensional models due to flux being partially carried in areas that are electrically shunted, and also lower due to the imperfect pinning.