Micromagnetic Studies of Finite Temperature M–H Loops for FePt-C Media

We have recently developed a new micromagnetic method at finite temperature, where the Hybrid Monte Carlo method is employed to realize the Boltzmann distribution with respect to the magnetic free energy. Hence, the hysteresis loops and domain structures at arbitrary temperature below the Curie point T_\rm c can be simulated. The Hamilton equations are used to find the magnetization distributions instead of the Landau–Lifshitz (LL) equations. In our previous work, we applied this method on a simple uniaxial anisotropy nano-particle and compared it with the micromagnetic method using LL equations. In this work, we use this new method to simulate an L10 FePt-C granular thin film at finite temperatures. The polycrystalline Voronoi microstructure is included in the model, and the effects of the misorientation of FePt grains are also simulated.