LAUSR

Abstract CoFe2O4 and MnFe2O4 nanoparticles were obtained by hydrothermal synthesis method in aqueous and in gelatinous media, at 175 °C and 230 °C. The structural, morphological and magnetic characterization of all samples was performed using different techniques: XRD, SEM, TEM, SQUID magnetometry and 57Fe Mossbauer spectroscopy. Their ability to be used as nanoheaters for magnetic hyperthermia applications was evaluated by determining their heating efficiency in aqueous suspension. The mean size of the CoFe2O4 nanoparticles ranges from 4.2 to 6.7 nm, while larger nanoparticles with broader distributions were obtained for the MnFe2O4 nanoparticles (from 4.4 to 17 nm). It was shown that both the temperature of the thermal treatment and the medium influence the mean size and size distribution of the nanoparticles, with the gelatin-assisted synthesis method producing nanoparticles with the highest specific heating ability. MnFe2O4 nanoparticles synthesized at 175 °C in gelatine medium display one of the best reported heating efficiency for manganese ferrite with values comparable to those of commercial magnetic nanoparticles.