As magnetic head recording frequencies have increased in recent years, the effects of magnetic field phase delay caused by eddy currents have become increasingly apparent. Simulation-based magnetic field analysis and optimal design are effective methods for improving this phase delay and carrying out development of magnetic heads suited to high recording frequencies.

Here, we have evaluated the merits of ANSYS and JMAG with respect to excess eddy current analysis for thin-film heads. In conclusion, our calculations were carried out by creating a mesh model using the ANSYS pre/post solid modeler/mesher, and then reading that model into JMAG-Works via a NASTRAN format file. Using the results of this analysis, we measured the write time shift to evaluate the eddy current-caused recording field phase delay and, comparing results obtained from models using different yoke lengths and properties, attempted to design a head suited to high recording frequencies. The results appear to indicate that it would be possible to design a head able to handle bit frequencies of 1 Gbps by shortening the head’s magnetic path and by using high Rho NiFe for its materials.