Materials Chemistry and Physics, Vol.140, No.1, 42-48, 2013
Impact of transition metal doping on Mossbauer, electrical and dielectric parameters of structurally modified lithium ferrite nanomaterials
Zr-Mn doped spinel lithium ferrites Li0.5Fe25-2xZrxMnxO4 (0.0 <= x <= 0.5) are synthesized using the citrate precursor method. The spinel ferrite is formed at a relatively lower annealing temperature (873 K) compared to those synthesized by other conformist methods. Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis are carried out to determine the cell parameters, crystallite size and grain growth. Cation distribution and site preferences for the doped ions are determined by Mossbauer spectroscopy at room temperature. The impact of doping of Li0.5Fe2.5O4 with the binary mixtures of transition metals (Mn, Zr) on hyperfine interaction parameters (delta, Delta and H-int), electrical resistivity (rho), dielectric constant (epsilon') and dielectric loss tangent (tan delta) over the frequency range of 100 Hz to 3 MHz is discussed in details. Zr-Mn doping enhanced the DC electrical resistivity and decreased the loss tangent value which is considered useful for technological application in microwave and telecommunication devices. (C) 2013 Elsevier B.V. All rights reserved.