| 摘要 |
PROBLEM TO BE SOLVED: To avoid the reduction or the loss of a reproduced output caused by the demagnetization or degaussing produced by the movement of the magnetic wall of a substrate soft magnetic film during a recording and a reproducing by using the perpendicularly magnetized two layer record medium, which is made by combining an under soft magnetic film and a perpendicularly magnetized film so that the output fluctuation against the magnetic field, which has the value less than a specific value and is applied in any directions in the space, is maintained at less than the specific value obtained prior to the application of the magnetic field. SOLUTION: An FeSiAl film 16 is formed on a substrate 12 and a Co78 Cr19 Ta3 perpendicularly magnetized film 18 is formed on the film 16 to make a perpendicularly magnetized record medium 10. Note that no clear magnetic wall structure is observed in the film 18. Having recorded signals on the medium 10 by a single magnetic pole/MR composite head, a direct current magnetic field is applied by a Helmholtz coil and then, a comparison is made between the reproduced output obtained prior to the application of the magnetic field and the reproduced output obtained after the application of the magnetic field. As a result, the fluctuation in the reproduced output is made within 5% against the applied magnetic field of less than 50 [Oe] and a good stability in the output is maintained. Thus, a high recording density is easily realized. |
