Micromagnetic study of side-writing phenomena using thin-film heads and Co–CoO metal-evaporated tape

Abstract

The recording process and the relationship between the side-written band and the pole shape of thin-film recording heads, which have an upper pole with a narrow track width and a trimmed lower pole, using Co–CoO, obliquely evaporated magnetic tape, have been investigated. In nonazimuth recording, the lower pole of the thin-film head on the trailing side is better than that on the leading side for generating a sharp-edged, side-writing band. In azimuth recording, the relationship between side-writing phenomena and the pole shape of a thin-film head is complicated, because the position recorded by the leading gap-field shifts across the track width from that recorded by the trailing gap-field due to the azimuth angle. The thin-film recording head with trapezoidal upper and lower poles to minimize the effect of the side-fringing field can generate a sharp-edged, side-writing band, particularly in azimuth recording, but it is critical that the lower pole be on the trailing side. The thin-film recording head, which has a trapezoidal upper pole on the leading side and a trapezoidal lower pole on the trailing side, is most effective in generating a sharp-edged, side-writing band.