Wall Pinning Effect of Co-Zr-Nb Main-Pole Film on Recording Characteristics of Single-Pole Heads

The effect of the domain structure in main-pole film on the reproducing sensitivity was investigated for various single-pole type perpendicular magnetic heads. The reproducing sensitivity of heads made of a Co-Zr-Nb single-layer film becomes unstable and decreases with increasing closure domain size when the track width narrows and the anisotropy field H
k
decreases. On the other hand, when the walls of closure domains are pinned by inserting small notches at both edges of a main-pole film, the magnetization rotates without any disturbance of the main domains. Using this novel method for controlling the domain structure, closure domains can be made smaller even for small H
k
, and a stable and highly sensitive single-pole head can be obtained.