Magnetic behavior and heating efficiency of CaFeO2 nanoparticles for magnetic hyperthermia applications

Magnetic properties and ac-field-induced heating behavior of CaFeO2 nanoparticles synthesized by the sol-gel method have been investigated. Structural characterization confirmed the formation of a single-phase orthorhombic oxygen-deficient perovskite-related phase. The temperature dependence of saturation magnetization and coercivity was studied and analyzed; the Curie temperature was estimated. A transition from ferromagnetic to superparamagnetic behavior was observed below room temperature. Calorimetric measurements were performed for aqueous ferrofluids containing CaFeO2 nanoparticles under alternating magnetic fields of various amplitudes. The field and concentration dependences of the specific loss power were analyzed. The results demonstrate that CaFeO2 exhibits favorable magnetic and thermal properties suitable for potential use in magnetic hyperthermia applications.