Structural, morphological, magnetic and dielectric characterization of nano-phased antimony doped manganese zinc ferrites

Nano-phased doped Mn-Zn ferrites, viz., Mn0.5-x/2Zn0.5-x/2SbxFe2O4 for x=0 to 0.3 (in steps of 0.05) prepared by hydrothermal method are characterized by X-ray diffraction, Infrared and scanning electron microscopy. XRD and SEM infer the growth of nano-crystalline cubic and hematite (alpha-Fe2O3) phase structures. IR reveals the ferrite phase abundance and metal ion replacement with dopant. Decreasing trend of lattice constant with dopant reflects the preferential replacement of Fe(3+)ions by Sb(5+)ion. Doping is found to cause for the decrease (i.e., 46-14 nm) of grain size. An overall trend of decreasing saturation magnetization is observed with doping. Low magnetization is attributed to the diamagnetic nature of dopant, abundance of hematite (alpha-Fe2O3) phase, non-stoichiometry and low temperature (800 degrees C) sintering conditions. Increasing Yafet-Kittel angle reflects surface spin canting to pronounce lower M-s. Lower coercivity is observed for x <= 0.1, while a large results for higher concentrations. High ac resistivity (similar to 10(6) ohm-cm) and low dielectric loss factor (tan delta similar to 10(-2)-10(-3)) are witnessed. Resistivity is explained on the base of a transformation in the Metal Cation-to-Oxide anion bond configuration and blockade of conductivity path. Retarded hopping (between adjacent B-sites) of carriers across the grain boundaries is addressed. Relatively higher resistivity and low dielectric loss in Sbdoped Mn-Zn ferrite systems pronounce their utility in high frequency applications. (C) 2016 Elsevier Ltd. All rights reserved.