Study on High Resolution Single-Pole Head in Reproduction

A thin main-pole film is required for high linear densities in perpendicular magnetic recording. In our experiments, Co-Zr-Nb films of thickness 0.08 ¿m had sufficiently low coercivity, but their domain wall structure nevertheless changed from Bloch walls to cross-tie walls at thicknesses under 0.1 ¿m. We found that main poles with cross-tie walls had much lower reproduction sensitivity than did those with Bloch walls. The thinnest main pole with a Bloch wall structure was 0.12 ¿m thick. It resulted in a high D50 of 170 kFRPI, and showed no deterioration of sensitivity.