Suitability of water based magnetic fluid with CoFe2O4 particles in hyperthermia

Magnetic susceptibility of the magnetic fluid with CoFe2O4 particles was measured in the low-frequency range in order to determine mean values of the magnetic grain size and the saturation magnetisation. The volume concentration of the solid phase (CoFe2O4) was also found. Results of the calorimetric measurements, in the range from 70 kHz to 1.7 MHz, confirmed the suitability of use of the medium studied in magnetic fluid hyperthermia, especially in the frequency region 600–800 kHz. The H2–law-type dependence of the specific absorption rate on the square amplitude of the magnetic field testified to the presence of superparamagnetic particles in the magnetic fluid. The minimum magnetic field intensity needed for successful hyperthermal treatment was experimentally determined.