Magnetic heating of triethylene glycol (TREG)-coated zinc-doped nickel ferrite nanoparticles

Triethylene glycol (TREG)-coated nickel-zinc (Ni-Zn) ferrite nanoparticles were synthesized via the hydrothermal method and characterized for application to magnetic hyperthermia. Ni-Zn ferrite particles of Ni1−xZnxFe2O4 with three different zinc contents of x = 0.2, 0.4, and 0.6 were formulated to investigate the structural and magnetic properties according to the zinc content. Transmission electron microscopy images revealed that the particles were spherical in shape and that the average diameters of the particles were 10.67, 13.02, and 18.73 nm for zinc contents of 0.6, 0.4, and 0.2, respectively. Fourier transform infrared spectroscopy confirmed that the TREG was firmly coated on the surface of the particles. The saturation magnetization decreased with the increasing zinc content in the particles, which affected the heating ability of the particles in the alternating magnetic field. The heating ability of the Ni0.8Zn0.2Fe2O4 and Ni0.6Zn0.4Fe2O4 particles facilitated the aqueous solution of these particles to reach the target temperature of 42 °C for magnetic hyperthermia, while an aqueous solution of Ni0.2Zn0.8Fe2O4 particles with a high particle concentration did not reach the target temperature. The high specific absorption rates of the Ni0.8Zn0.2Fe2O4 and Ni0.6Zn0.4Fe2O4 particles indicate that these particles are applicable to magnetic hyperthermia.