| 摘要 |
PURPOSE:To obtain a thin film magnetic head possible for high density recording by decreasing the thickness of the 2nd magnetic layer more than that of the 1st magnetic layer, providing the effect reducing the peak shift due to reproduced wave interference and adopting a high magnetic flux density material only for the 1st magnetic layer so as to increase the write magnetic field without changing the reproducing characteristic. CONSTITUTION:When the same film thickness is given to the 1st magnetic layer 3 and the 2nd magnetic layer 6, a difference is given to the undershoot produced to an isolate reproducing waveform and a peak shift where a position of a waveform peak located substantially is shifted takes place. Since the undershoot depends on the thickness of the magnetic layer, it is desired to make the thickness of the 1st magnetic layer 3 thinner than that of the 2nd magnetic layer 6, but if the 1st magnetic layer 3 is formed too thin, a magnetic saturation is caused to decrease the recording magnetic field. Thus, a magnetic material having a saturation magnetic flux density being nearly 1.2-1.4 time of that of the 2nd magnetic layer is used for the 1st magnetic layer to make the film thickness thin and avoid the magnetic saturation. Concretely, an Ni-Fe alloy is used for the 2nd magnetic layer, and an Ni-Co-Fe alloy is used for the 1st magnetic layer. |
