Effects of magnetic layer thickness on negative nucleation field and Cr segregation behavior in CoCrPt/Ti perpendicular media

Based upon our previous study on the formation of a large negative "nucleat ion field" in CoCrPt/Ti single layered perpendicular media (LS. Lee et al., J. Appl. Phys. 85 (1999) 6133), dependency of magnitude of negative nuclea tion field on CoCrPt/Ti with variation of Pt content and CoCrPt thickness w as investigated. Difference in the degree of Cr segregation with the film t hickness for a given film composition was also discussed. It was found that Cr segregation behavior might be closely associated with the nature of res idual stress in the magnetic layer. When there was tensile stress in the fi lm, Cr segregation was not significant. To understand the origin of the neg ative nucleation field, micromagnetic simulation was performed and it was f ound that a normalized nucleation field, H-n/K,(u) linearly depended upon K -u/M-s(2) and weakly depended on exchange parameter among grains when unifo rm grain size was assumed. Read/write simulation results show that a high n egative nucleation field is effective in increasing the signal output. (C) 2001 Elsevier Science B.V. All rights reserved.