Reproducing Sensitivity of Single-Pole-Type Head with Co-Zr-Nb/SiO2 Multilayered Films

Effects of domain structures in main pole films on the reproduction sensitivity are investigated for single-pole-type perpendicular magnetic recording heads. The reproduction sensitivity of a single-pole head adopting a Co-Zr-Nb single-layer film becomes unstable and decreases with increases in closure domain sizes, when the track width is made narrow and the anisotropy field Hk is low. On the other hand, for a narrow-track main pole made of Co-Zr-Nb multilayer film with a 50 Ã… thick SiO2 intermediate layer, closure domains cannot be observed clearly. Consequently the reproduction sensitivity becomes larger than that of the single-layer main pole, and the reproduced voltage is very stable even for lower Hk and narrower track widths.