Specific absorption rate determination of magnetic nanoparticles through hyperthermia measurements in non-adiabatic conditions

• Development and thermodynamic modelling of a hyperthermia setup operating in non-adiabatic conditions.
• Calibration of the experimental setup and validation of the model.
• Accurate measurement of specific absorption rate and intrinsic loss power in non-adiabatic conditions.

An experimental setup for magnetic hyperthermia operating in non-adiabatic conditions is described. A thermodynamic model that takes into account the heat exchanged by the sample with the surrounding environment is developed. A suitable calibration procedure is proposed that allows the experimental validation of the model. Specific absorption rate can then be accurately determined just from the measurement of the sample temperature at the equilibrium steady state. The setup and the measurement procedure represent a simplification with respect to other systems requiring calorimeters or crucial corrections for heat flow. Two families of magnetic nanoparticles, one superparamagnetic and one characterised by larger sizes and static hysteresis, have been characterised as a function of field intensity, and specific absorption rate and intrinsic loss power have been obtained.