Structural and dielectric properties of Sr1-xCexMgyFe2-yO4 nano ferrites synthesized by citrate gel auto combustion method

Abstract

A series of Sr1-xCexMgyFe2-yO4 (where x = y = 0.0, 0.25, 0.50, 0.75, and 1.0) nanoferrites were synthesised via the citrate gel auto combustion method. The synthesised materials structural and electrical properties were examined. Structural properties are investigated by x-ray diffraction analysis (XRD), SEM, and FTIR spectroscopy. X-ray diffraction analysis confirms the cubic spinel structure of the material. The crystalline size of the sample varied from 22 to 32 nm, whereas the lattice parameter was found to be 7.832 to 8.558 Ao. The lattice parameter's linear variation was not observed, which indicates that it does not obey Vegard's law. SEM images reveal those morphological characteristics, which are spherical shapes. EDAX confirms the presence of Sr, Ce, Mg, Fe, and O in the synthesised samples. FTIR spectra confirm the spinel structure with two sublattices, namely, tetrahedral and octahedral sites. Electrical properties carried out by LCR meter at different frequencies and dielectric parameters such as dielectric constant, dielectric loss, AC conductivity, and impedance spectra have been studied. Dielectric constant and loss decreased with increasing frequency, whereas AC conductivity increased. It was explained by the Maxwell-Wagner polarisation theory. A single semicircle type of behaviour was observed in Cole-Cole plots.