Abstract
Perpendicular magnetic recording is one method of achieving high-density recording. In perpendicular magnetic recording using a single-pole-type (SPT) head, it is necessary to use a main pole film that works stably. In this respect, use of a single-layered main pole film has a serious limitation because of its domain structure. On the other hand, a multilayered main poleisthought to have no limitation,because the closure domain will be eliminated by magnetic coupling. However, SPT headsusing multilayered thin nlms often show instability in the reproduction process. We found that theinstability could be removed by applying a dc magnetic field to the multilayered main pole. The stressin the multilayered film was related to theinstabilityin the head's behavior. We also showed that an underlayer between the magnetic layer sand the substrate is necessary to eleminate the stress in multilayered films.
