Atomistic spin model simulation of magnetic reversal modes near the Curie point

In order for the current increase in magnetic storage density to continue, one must overcome the so-called magnetic recording trilemma; namely, that smaller grains are required for higher data densities and to ensure their thermal stability, materials with a high anisotropy are required. The higher coercive field that this produces also becomes a limiting factor as the maximum field produced by the recording head is constrained by the saturation magnetization of the pole. One proposed solution to the trilemma is the use of heat assisted magnetic recording HAMR, which utilizes the temperature dependence of the anisotropy to enable writing of materials with a high coercivity. For the highest anisotropy media, this will require heating to the Curie temperature TC of the material. Close to TC, longitudinal fluctuations in the magnetization can have a significant impact on the expected energy barriers and therefore the relaxation time of the magnetization. These effects become especially important when attempting to minimize the time to reverse the magnetization state of the media that will be important at higher storage densities.