Micromagnetic modelling of new generation of FePt and FeRh nanostructures for heat assisted magnetic recording

Abstract High magnetocrystalline anisotropy FePt can be considered to be a potential candidate for increasing the areal recording density up to ∼1 Tb in−2. The writing head fields available are not adequately high for magnetic reversal (writing) because of the high coercivity of FePt. However, by uniquely combining FePt and FeRh, we can overcome the writing field limitation in the heat assisted magnetic recording approach. In this regard, we describe individually simulated FeRh and FePt nanodot cuboids and comparison of the data with the experimental observations made on FePt and FeRh nanoparticles. Furthermore, the hysteresis behaviour of FeRh/FePt bilayer cuboids was simulated with different values of the exchange constants, and the dependence of coercivity on the exchange constant was examined. The FePt/FeRh bilayer cuboids experienced a typical two-stage magnetic reversal, and the effects of the exchange constants on the reversal and coercive fields were examined.