Site Occupancy, Surface Morphology and Mechanical Properties of Ce3+ Added Ni–Mn–Zn Ferrite Nanocrystals Synthesized Via Sol–Gel Route

Abstract

Ferrite nanoparticles of Ni[Formula: see text]Mn[Formula: see text]Zn[Formula: see text]Fe[Formula: see text]Ce x O 4 ferrite system were produced using sol–gel auto combustion technique. X-ray diffraction analysis confirms the single phase cubic spinel structure of the samples with space group Fd-3m. Replacement of Fe[Formula: see text] ions by Ce[Formula: see text] ions increases the lattice parameter 8.4105 Å to 8.4193. Average crystallite size obtained from Scherrer method varies from 21.73[Formula: see text]nm to 22.71[Formula: see text]nm with replacement of Fe[Formula: see text] ions by Ce[Formula: see text] ions. Williamson–Hall and strain-size plot analysis confirms the nanocrystalline nature of the samples and the micro-strain induced in the cubic crystals is of tensile type. Cation distribution suggests that Zn[Formula: see text] ions occupy tetrahedral — A-site while Ni[Formula: see text] ions occupy octahedral — B-site. Majority of the Mn[Formula: see text] ions prefer A-site and majority of the Ce[Formula: see text] ions replace Fe[Formula: see text] ions at octahedral — B-site. High resolution transmission images confirm the homogeneity and nanoparticle nature of the samples. Two main characteristics absorption bands corresponding to spine structure are observed in the Fourier transmission infra-red spectra within the wavenumber range of 350–600[Formula: see text]cm[Formula: see text]. Stiffness constant, Young’s modulus, rigidity modulus, bulk modulus and Debye temperature were estimated using FTIR data. Debye temperature obtained from the Waldron equation varies from 676[Formula: see text]K to 692[Formula: see text]K with the addition of Ce[Formula: see text] ions. Higher values of elastic moduli are suitable for industrial applications due to increased mechanical strength.

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