Microscopic magnetic characteristics of CoCrPt-patterned media made by artificially aligned self-organized mask

The microscopic magnetic characteristics of CoCrPt-patterned media after magnetic recording by a ring head were investigated. The media consists of two rows of aligned CoCrPt dots with a diameter of 40 tun. The magnetization reversal of each dot is clearly observed by magnetic force microscopy (MFM). A few misreversed dots were observed in the written "bit" patterns. The distribution of coercivity H-c was investigated by MFM using dot-by-dot analysis. It was found that H-c is about 4 kOe on the average with a wide distribution ranging from 0.5 to 7.5 kOe. This large distribution of H-c causes these magnetization reversal defects. One possible origin of the large H-c distribution is the grain boundary observed in each grain of the CoCrPt layer.