Thermally induced magnetization switching in Gd/Fe multilayers

A theoretical model of Gd/Fe multilayers is constructed using the atomistic spin dynamics formalism. By varying the thicknesses and number of layers we have shown that a strong dependence of the energy required for thermally induced magnetization switching (TIMS) is present; with a larger number of interfaces, lower energy is required. The results of the layer resolved dynamics show that the reversal process of the multilayered structures, similar to that of a GdFeCo alloy, is driven by the antiferromagnetic interaction between the transition-metal and rare-earth components. Finally, while the presence of the interface drives the reversal process, we show here that the switching process does not initiate at the surface but from the layers furthest from it, a departure from the alloy behavior which expands the classes of material types exhibiting TIMS.