Influence of heat treatment on magnetic, structural and elastic properties of as-prepared Mg-nanoferrites

This investigation presents the effect of heat treatment on the magnetic, structural and elastic properties of as-prepared MgFe2O4 nanoferrites. Five amounts of MgFe2O4 nanoparticles were heating at a different temperature for each one. The techniques used for examine the samples were XRD, VSM and FT-IR and Mossbauer spectra. Heating the samples at different temperatures led to increasing the crystallite size R from 3 to 81 nm and saturation magnetization M-s from 5.4 to 17.1 emu/g. The theoretical and experimental density and strain showed increase against heating temperature T, whereas the porosity P, oxygen parameter, specific surface area, distortion parameter showed decrease and the lattice constant and parameters showed independence on T. Seven absorption bands were observed in the IR spectra where the positions of bands v(1) and v(2), force constants. Debye temperature and stiffness constant C-11 were decreased with T, whereas the trend of stiffness constant C-12 were increased. Mossbauer spectra proved that the hyperfine magnetic fields and line widths of the magnetic pattern at the A- and B-sites and fractional area ratio were affected by T. The cation distributions were deduced. The coercivity, squareness and crystal anisotropy constant showed independence on T whereas the remanent magnetization and magneton number showed dependence and Ms proved dependence on P and R. (C) 2015 Elsevier B.V. All rights reserved.