HIGH-FREQUENCY HEAD AND PLAYBACK MODEL FOR THIN-FILM RECORDING-HEADS

A thin-film head field and readback model that allows for eddy currents has been proposed and used to compute complex head efficiency, inductance, anomalous (ac) resistance, head saturation fields and locations, as well as the digital playback parametrics high and low frequency amplitude, resolution, PW-50, and maximum overwrite fields with a fair amount of accuracy. The head model solves for the time-dependent vector potential in a geometry that closely resembles a modern three dimensional thin-film recording head, including variable pole and yoke width, thickness, permeability, resistivity, neck angle and other geometrical parameters. Readback emulation is done with a discrete Fourier version of the reciprocity integral using Szczech fields and arctan transitions, along with complex efficiencies from the head model. Detailed comparisons with experimental observations are given.