Track edge phenomena in thin film longttudinal media

Isolated transitions, recorded with a thin-film inductive head on thin-film isotropic media and read with a magnetoresistive sensor can exhibit waveform distortions, characterized by a shift of the base line between readback pulses. The amount of the base-line shift (BLS) increases with increasing write current, decreasing trackwidth and decreasing medium coercivity. The source of the BLS is shown experimentally to be localized at track edges. A model, based on the creation of magnetic dipoles along each edge of a data track is proposed to explain the observed waveform deformation. Quantitative measurements of the BLS as well as the dipole-width estimation are presented. © 1989 IEEE