Thermal stability and read-write performance of AFC media

The effect of the magnetic properties of the lower layer, of the antiferromagnetically coupled (AFC) media on thermal stability and the signal-to-noise ratio (S_1F/N_d2F) was studied using a Monte-Carlo simulation and the Langevin equation. Thermal stability was the highest when the largest M_s2 value was used within the limits of achieving antiferromagnetic coupling between the magnetic layers, and when the value K_u2 was less than the value of the upper layer. S_1F/N_d2F increased linearly with a decrease in the anisotropy field H_k2 at the rate of 0.5 dB per 100 kA/m.