Characteristics of Particulate Heating Mediator in RF Capacitive Heating

Characteristics of particulate heating mediators in radiofrequency (RF) capacitive hyperthermia were investigated. Four ferromagnetic ferrite particles (Cu (II) Fe (III)_2 O_3 , Mg (II) Fe (III)_2 O_3 , Mn (II) Fe (III)_2 O_3 , and Ni (II) Fe (III)_2 O_3 ) in addition to magnetite particles and other non-ferromagnetic metal oxide particles (α-Fe_2 O_3 , α-Alumina, Ag (II) O, and ZnO) were tested using 8 MHz RF heating device. As a result, ferromagnetic particles could generate heat specifically in RF capacitive, but non-ferromagnetic particles could not. In addition, dispersiblity of particles was an important parameter for heat generation. Temperature increase of Mg (II) Fe (III)_2 O_3 was well improved by sonication. It was shown that alternative magnetic field is generated around ferromagnetic particles in 8 MHz RF electric field and that heat is generated in ferromagnetic particles due to hysteresis loss by the action of alternative magnetic field; i. e. the same heat generation mechanism with inductive heating.