Sol-gel synthesis of MnxGa1−xFe2O4 nanoparticles as candidates for hyperthermia treatment

Sol-gel synthesis of novel MnxGa1−xFe2O4 (x=0–1) magnetic nanoparticles (MNP's) was studied. An inverse spinel crystalline structure was identified for all samples. Magnetization saturation values (Ms) were in the range of 21.4–42.6 emu/g, while coercive field (Hc) was less than 27.4 Oe in all cases. Selected compositions of MnxGa1−xFe2O4 (x=0.6, 0.8) showed nanoparticles with near-spherical morphology and average size of 15 nm. Magnetic induction curves indicate that a suspension concentration of MNP's equal or higher than 4.5 mg/mL was sufficient to reach the temperature required for hyperthermia treatment (>43 °C) in less than 10 min. The incorporation of Mn ions into the crystalline structure led to an increase of the magnetic response of the MNP's when an alternate magnetic field was applied, requiring a shorter time of exposition and a low dose of MNP's, which make these nanoparticles potential candidates for magnetic hyperthermia.