Structural, Magnetic, and Mössbauer Investigation of Mg-Ni-Co ferrites doped by Sm3+ sions

Abstract Samarium-doped magnesium-nickel-cobalt nanoferrites (Mg 1/3 Ni 1/3 Co 1/3 )Fe 2−x Sm x O 4 , with x = 0.00, 0.01, 0.02, 0.04, and 0.08, were synthesized by the coprecipitation method. X-ray diffractometer (XRD), transmission electron microscopy (TEM), energy dispersive x-ray (EDX), x-ray photoelectric spectroscopy (XPS), Fourier Transform Infra-Red (FTIR), Raman spectroscopy, Mössbauer spectroscopy, and magnetic measurement techniques were used, to study the structure, microstructure, and magnetic properties of the samples. The formation of the cubic spinel structure was confirmed by Rietveld analysis of the XRD data and by the appearance of the two absorption bands close to 400 cm −1 and 600 cm −1 from the FTIR spectrum. Raman spectroscopy verified the formation of the spinel phase in the samples. The elemental composition, valency, and cationic distribution were examined using x-ray photoelectric spectroscopy (XPS) measurements. Experimental findings revealed that doping with Sm 3+ ions had a significant effect on the magnetic properties of nanoparticles. The saturation magnetization ( M s ) and coercivity field ( H c ) values fluctuate depending on the crystallite size (D XRD ) of the samples from XRD analysis as the Sm 3+ content increases. The magnetization dependence on the applied field was investigated at different ranges of applied fields based on the output of the statistical parameters for the curve fitted using four different forms of the law of approach to saturation. The statistical parameters and physically significant fitted parameters give information on the dependence of magnetization over various applied field regions. A thorough investigation of the output parameters from fitting into various equations reveals that the composition of Mg-Ni-Co ferrites exhibits a dependence of magnetization on the applied field. Room-temperature Mössbauer spectra displayed a mix of the magnetic sextet and central quadrupole doublet, with improvement in the magnetic sextet in the Sm-doped samples. Moreover, Mössbauer spectra at 77 K showed the demise of the quadrupole doublet in all samples and showed two sextets (tetrahedral and octahedral sites). Sm-doping reduced the values of the hyperfine magnetic field of both sextets. All Fe ions can be found in the Fe 3+ state, according to the isomer shift values and there is a migration of Fe 3+ ions from octahedral to tetrahedral sites upon Sm doping, which was confirmed by XPS measurements.