Characterization of anisotropy field dispersion in perpendicular media

Two of the most publicized methods for anisotropy field dispersion characterization, the M-H loop method and the complex transverse susceptibility (TS) method, are evaluated with micromagnetic simulation. For the M-H loop method, the measured parameter is found to be dependent on grain saturation magnetization and easy axis dispersion, but only weakly dependent on intergranular exchange. It also depends on the dispersion of the anisotropy field as originally proposed. For the complex TS method, the technique is calculated to be most dependent on the intergranular exchange and exhibit little dependence on microstructure.