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 Hk 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 Hk, and a stable and highly sensitive single-pole head can be obtained.