Effect of heat treatment on Mn_xZn_(1-x)Fe₂O₄ nanoparticles prepared by mechanochemical method using metal oxides

G. V. S. Kundaikar
Department of Physics, Goa University, Taleigio, Goa – 403 206, India.

Carbon – Science and Technology 5/2 (2013) 275 – 284.
Advanced (Non-Carbon) Materials Section

© Applied Science Innovations Private Limited, India.

Full Text (OPEN ACCESS) : CST-72.pdf

Keywords: Nanoparticles, mechanochemical synthesis, Mn_xZn_(1-x)Fe₂O₄, metal oxide, heat treatment

Abstract: Nanoparticles of Mn_xZn_(1-x)Fe₂O₄ where x = 0.625, 0.65 and 0.675 with grain size ranging between 15 nm – 25 nm were prepared by novel technique employing low temperature autocombustion. XRD, IR and TEM techniques were used to obtain structural and morphological characterizations. XRD and IR spectra confirmed the formation of spinel structure. Stoichiometry of the samples was confirmed with EDS spectral analysis. Nanocrystalline nature of the sample was observed in HRTEM of the samples and formation of the nanoparticles was confirmed by measuring crystallite size using XRD pattern and TEM. Magnetic properties of the nanosample obtained with VSM give values ranging between 45.25 – 50.92 emu/gm;0.0009 - 0.0055 Tesla, and 2.77 – 9.4 emu/gm for saturation magnetization, coercivity and retentivity, respectively. Curie temperature values ranging between 380⁰C – 540 ^oC were obtained for the powdered samples. Magnetic measurements like saturation magnetization Ms, coercivity Hc, and retentivity Mr, carried out on the bulk samples obtained at 900 ^oC show that the samples lose the magnetic properties and behaved as paramagnetic material.