Review Article

Recent Advances in Understanding Magnetic Nanoparticles in AC Magnetic Fields and Optimal Design for Targeted Hyperthermia

Figure 1

Schematic diagrams of conventional models for magnetic loss. (a) Hysteresis loss equivalent to the area of loop, and the potential energy in magnetic fields. (b) Relaxation loss given by the out-of-phase component of AC susceptibility. As illustrated in the sketches, in Néel relaxation, the magnetic moment shown by the yellow arrow reverses (the particle does not rotate), while in Brownian relaxation, the magnetic core (the red sphere) rotates with absorbed molecules (the green chains) as a whole (the magnetic moment does not reverse).
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(a)  Hysteresis loss
752973.fig.001b
(b) Relaxation loss