Langevin dynamic simulations of magnetic hyperthermia in rotating fields

The effect of a rotating magnetic field on heat dissipation due to magnetic hyperthermia is investigated numerically. A robust and validated in-house code based on Langevin Dynamics is used. High order asymptotic solutions of the temperature rate are used to validate the numerical approach. Comparisons between a rotating and an oscillatory excitation indicate a nonlinear response of the magnetic suspension with respect to the amplitude and frequency of the field. The relaxation time and volume fraction of particles also play a relevant role in this dynamics. A complete analysis on the effect of these parameters on the thermal response of the system is presented. The timescales of the problem and geometric features of the suspension micro-structure are used to interpret the results. Hysteresis curves and the real and imaginary components of the complex susceptibility are also presented in order to provide a clear physical description of the problem.