Significance of δM Measurements in Thin Film Media

Remanence measurements have been proposed as a means of estimating the amount of intergranular exchange present in thin film recording media. A micromagnetic model is used to compute remanence curves starting from a dc-saturated state and an ac-erased state, for a range of media parameters. It is found that the amount of intergranular exchange is the most important parameter determining the difference δMbetween these two curves, however the interpretation is clouded somewhat by the effect of anisotropy and other parameters. © 1991 IEEE