On the specific absorption rate of hyperthermia fluids

The specific absorption rate (SAR) concept of hyperthermia ferrofluids is discussed. It is first suggested that SAR can be characterized at the steady state condition, taking into account the heating flow mechanism from the ferrofluid to the external environment. The temperature dependence of SAR is then addressed, indicating that the influence arises from both magnetic susceptibility and relaxation time of the system. At last, a single equation able to express the temperature versus time profile of a ferrofluid, when SAR is virtually temperature independent, is proposed up to the equilibrium condition. (C) 2013 AIP Publishing LLC.