Composite Media for Heat Assisted Magnetic Recording

Composite media grains consisting of two discrete magnetic layers with different uniaxial anisotropies, K_u, and Curie temperatures, T_c , were investigated for heat assisted magnetic recording. The maximum switching probability of optimized composite grains exceeded that of single phase grains. As K_u of one layer increased the optimum K_u of the other layer became smaller, tending toward zero in many cases. Leading and trailing edge recording were also compared. Trailing edge recording was superior when the maximum temperature in the grain, T_max , was similar to T_c , but when T_max exceeded T_c leading edge recording performed better.