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 µm had sufficiently low coercivity, but their domain wall structure nevertheless changed from Bloch walls to cross-tie walls at thicknesses under 0.1 µm. We found that main poles with crosstie walls had much lower reproduction sensitivity than did those with Bloch walls. The thinnest main pole with a Bloch wall structure was 0.12 µm thick. It resulted in a high D50 of 170 kFRPI, and showed no deterioration of sensitivity.
ASJC Scopus subject areas
- Engineering (miscellaneous)