Effect of anisotropy field magnitude distribution on signal-to-noise ratio

Recording performance is analyzed by a micromagnetic model in two thin film media with different distribution width of the anisotropy field magnitude. With the same M/sub r//spl delta/, the magnetic properties of the two media are almost the same except that the switching slope S* is larger for the medium with narrower distribution. The signal-to-noise ratio (SNR) is calculated for both media versus recording densities. The SNR at recording densities 4800-9000 flux reversals per millimeter is 5-8 dB smaller in the medium with a broad anisotropy magnitude distribution than the SNR in the medium with a sharp distribution.