3.3.2. Heat Production Mechanisms in MHT

MHT relies on the conversion of magnetic energy into thermal energy by the action of an alternative magnetic field with a frequency usually ranging from 100 to 300 kHz and a moderate amplitude [53,54,66]. Four independent mechanisms contribute to heat production: eddy current loss, hysteresis loss, Néel relaxation loss, and Brown relaxation loss [48,53,57]. The relative contributions of these four effects are determined by particle size, magnetic anisotropy, and fluid viscosity. The specific absorption rate (SAR) expressed in W/kg, quantifies the thermal power dissipation. SAR increases in proportion to the thermal energy released in the material [57]. The physical basis of MHT is well described elsewhere [48,54,57,96].
