Magnetic Recording
Effect of Domain Structure of Main Pole Film on Reproducting Sensitivity of S.P.T. Head
1985 Volume 9 Issue 2 Pages 79-82
Details
1985 Volume 9 Issue 2 Pages 79-82
The domain structures of narrow track single pole heads for perpendicular magnetic recording have been observed and their effects on the reproducing sensitivities are investigated. The ratio of the double height 2h of the closure domain to the track width W increases when the track width and the anisotropy field Hk of a Co-Zr-Nb amorphous main pole film decrease. The maximum reproducing sensitivity for each narrow track head is obtained for the optimum value of Hk, when the ratio of 2h to W is about 30%. When the Hk is smaller than the optimum value giving the maximum sensitivity, the reproduced voltage not only decreases but also changes with every cycle of recording. On the other hand, the reproduced voltage does not change and becomes smaller for larger Hk, because the permeability of the film decreases. The reproducing sensitivity of the narrow track single pole head, made of the film having the optimum Hk, does not decrease even for the head of 10 μm wide track.
