Domain Structures of Co-Zr-Nb Amorphous Main-Pole Film and Characteristics of Perpendicular Magnetic Recording

Domain structures of Co-Zr-Nb amorphous film for use as the main poles of single-pole perpendicular magnetic recording heads have been observed using the Bitter method. A narrower Co-Zr-Nb main pole with a low Hk showed a disordered domain structure near its tip in the remanent state. This in turn caused low and unstable sensitivity of the narrow-track single-pole head. Rotation magnetization of major domains is dominant in the magnetization of stable main poles. A stable and highly sensitive single-sided single-pole head was obtained by using a shorter main pole with an aspect ratio of about 1; this pole had an ordered and stable domain structure even in the remanent state.