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 H
k
is low. On the other hand, for a narrow-track main pole made of Co-Zr-Nb multilayer film with a 50 Å thick SiO
2
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 H
k
and narrower track widths.