An analysis of the write performance on thin film head

The write/read performance of a thin-film head was studied by using simple single-turn stepped head. Yoke length and pole-face length are varied from 30 μm to 120 μm and from 3 μm to 6 μm, respectively. The read efficiency was well explained by the transmission line model. It was clarified that the magnetomotive force for saturation magnetic recording is expressed by a formula which consists of a constant term and a term proportional to the yoke length. The former term is corresponding to the minimum field to saturate a recording media, while latter is determined by the reluctance of the yoke. For more detailed analysis, the field produced by the head having a yoke semi-infinite in length is numerically calculated from the magnetization distribution determined so as to minimize the total magnetic energy. The result of the calculation explains the pole-face length dependence of the magnetomotive force for saturation recording.