Effect Hyperthermia in CoFe2O4@MnFe2O4 Nanoparticles Studied by using Field-induced M¨ossbauer Spectroscopy

Effect Hyperthermia in CoFe2O4@MnFe2O4 Nanoparticles Studied by using Field-induced M¨ossbauer Spectroscopy

CoFe2O4@MnFe2O4, with a mixed core-shell structure was fabricated by a high temperaturethermal decomposition. From the Rietveld refinement, these nanoparticles were found to be cubicspinel with space group Fd−3m and with a Bragg factor (RB) and a structure factor (RF ) less than5%. The size and the shape of the nanoparticles were examined with high-resolution transmissionelectron microscopy (HR-TEM). The values of the magnetization (MS) and the coercivity (HC) ofthese nanoparticles at room temperature were 78.95 emu/g and 21.2 mT, respectively. The effectof hyperthermia, measured with a magneTherm device showed that the self-heating temperatureof the nanoparticles could reach 133 C. To determine the applicability of nanoparticles in hyperthermiatherapy, we evaluated the in-vitro cell viability of nanoparticles. Based on the probabilitydistribution of cations, we determined the M¨ossbauer spectra at 4.2 K with two sets of six linesunder various applied fields parallel to the direction of the-rays. To separate the A and the Bsites, we also obtained the M¨ossbauer spectra of the nanoparticles under high external field up to5 T at 4.2 K. From the detailed analysis of the M¨ossbauer spectra, the spin canting angles and theanisotropy energies at the A and the B sites were determined.

CoFe2O4@MnFe2O4, with a mixed core-shell structure was fabricated by a high temperaturethermal decomposition. From the Rietveld refinement, these nanoparticles were found to be cubicspinel with space group Fd−3m and with a Bragg factor (RB) and a structure factor (RF ) less than5%. The size and the shape of the nanoparticles were examined with high-resolution transmissionelectron microscopy (HR-TEM). The values of the magnetization (MS) and the coercivity (HC) ofthese nanoparticles at room temperature were 78.95 emu/g and 21.2 mT, respectively. The effectof hyperthermia, measured with a magneTherm device showed that the self-heating temperatureof the nanoparticles could reach 133 C. To determine the applicability of nanoparticles in hyperthermiatherapy, we evaluated the in-vitro cell viability of nanoparticles. Based on the probabilitydistribution of cations, we determined the M¨ossbauer spectra at 4.2 K with two sets of six linesunder various applied fields parallel to the direction of the-rays. To separate the A and the Bsites, we also obtained the M¨ossbauer spectra of the nanoparticles under high external field up to5 T at 4.2 K. From the detailed analysis of the M¨ossbauer spectra, the spin canting angles and theanisotropy energies at the A and the B sites were determined.