Magnetic Heating of Fe-Co Ferrites: Experiments and Modeling.

Magnetic nanoparticle hyperthermia uses magnetically-induced heat to kill cancer cells. In an alternating magnetic field, the induced heat depends strongly on particles' absorption properties. In order to achieve and maintain therapeutic temperatures inside a tumor and to minimize damage to normal tissues due to induced eddy currents, there is a need to develop new magnetic nanoparticles with improved heating characteristics. This paper investigates the magnetic heating properties of composite iron-cobalt ferrite nanoparticles Co x FeII1-x FeIII2O4 with 0≤x≤1. These composite materials are synthesized using a precipitation method. First, the Fe-Co nanoparticle synthesis is described, then their structure, size, magnetic and heating properties are measured and analyzed. The resulting nanoparticles were treated at temperatures 100-600°C in order to study any structural transformations and changes of physical properties. Finally, an empirical model is used to calculate both the nanoparticles' coercivity and their specific absorption rates for different Co concentrations.