Magnetic properties and hyperfine interactions of Co1-2xNixMnxFe2O4 nanoparticles

Abstract

Co1-2xNixMnxFe2O4 (0.0≤x≤0.5) nanoparticles (NPs) were prepared via citrate assisted microwave combus-tion route. XRD analysis confirmed the cubic structure (spinel) of all samples. Average crystallite size ofproducts (obtained from (311) diffraction line) was in the range of 32.9–43.4 nm. The intense peak appearing ataround 531 cm−1in FT-IR was attributed to the formation of a spinel ferrite. Magnetic properties of theproducts were investigated by room temperature vibrating sample magnetometer and Mössbauer spectroscopy.The magnetic parameters have been found to strongly depend on the Ni and Mn concentrations. The saturationmagnetization continuously decreases with the increasing of the concentration (x). We found thatNi0.5Mn0.5Fe2O4NP has superparamagnetic character at room temperature. This result was also verified byMössbauer analysis. Scanning electron microscopic analysis revealed the cubic morphology of all products, EDXand elemental mapping analyses confirmed the expected composition of each product.