In order to estimate the thermal stability of a keepered medium with a soft magnetic under-layer or an antiferromagnetically coupled medium of two laminated recording layers with a thin intervening nonmagnetic layer, a finite element read/write simulation based on the Poisson equation is performed at finite temperatures on the 2D model of the medium and a thin film head system. Using a Stoner-Wohlfarth model extended at finite temperatures, the thermal stability is estimated by the difference between the output voltage at just after recording and one at quasiequilibrium state at 300K or by the time-dependence of the output voltage. As a result, it is found that both media have high thermal stability compared with the conventional media.
