MAGNETIC-INTERACTIONS IN COCR THIN-FILMS

Both the isothermal remanent magnetization and the dc demagnetization remanence were measured on thin films of CoCr with a perpendicular ani sotropy energy suitable for perpendicular recording media. The measure ments were made with two applied magnetic field geometries, parallel a nd perpendicular to the film plane. Plots of the dc demagnetization re manence versus the isothermal remanent magnetization were used to dete rmine the presence of interactions for both applied magnetic field geo metries. As expected, the perpendicular magnetization process is domin ated by the demagnetization field. When the data are corrected for the demagnetization field, a residual negative interaction is found from the perpendicular data. This negative interaction was also observed in the parallel applied field geometry plots, where the demagnetization factor is negligible. The success of the analysis, using a mean-field approximation to model the interactions, which in this case is the dem agnetization field, suggests a general technique to quantify interacti ons in magnetic systems.