Microstructure, charge carrier conduction mechanism model, dielectric properties and leakage current analysis of Dy2FeMnO6 nanomaterial

The structure, microstructure, charge transport properties, dielectric properties, and leakage current density of Dy2FeMnO6 synthesized by the auto combustion method are investigated in this study. The monoclinic crystal structure of the sample with space group P21/n was observed. The CoO6 and MnO6 octahedra were found dis-torted and tilted. The calculation of the bond valence sum confirmed the +3 and + 3/+4 oxidation states of Fe and Mn, respectively. The average crystallite, particle, and grain sizes were 43.01, 94, and 187.68 nm, respec-tively. The anticipated stoichiometry of the constituent elements was confirmed by energy-dispersive X-ray spectra. The frequency-dependent conductivity obeyed Jonscher's power law, and the frequency exponent associated with this law increased with temperature, indicating the non-overlapping small polaron tunnelling (NSPT) mechanism for charge conduction. The enhancement of the dielectric loss tangent with temperature was consistent with the dc conductivity. The frequency dependence of dielectric properties was explained using Havriliak-Negami formalism. The sample followed Vogel-Fulcher law, which is similar to the relaxor ferro-electrics, and the ferroelectricity increased with frequency. Conduction, migration, and dielectric relaxation all have similar activation energies. The sample exhibited low leakage current density, which followed Schottky emission with a barrier height of 0.02(4) eV. The obtained results were compared with other rare-earth-based double perovskites.

Automated summary

This study investigates the properties of Dy2FeMnO6 synthesized by the auto combustion method, including its structure, microstructure, charge transport properties, dielectric properties, and leakage current density. The sample exhibits a monoclinic crystal structure with distorted and tilted CoO6 and MnO6 octahedra. The oxidation states of Fe and Mn are confirmed to be +3 and +3/+4, respectively. The sample shows non-overlapping small polaron tunnelling (NSPT) mechanism for charge conduction, and follows Jonscher's power law for frequency-dependent conductivity. The dielectric properties are described using Havriliak-Negami formalism, and the sample demonstrates Vogel-Fulcher law and ferroelectricity. The leakage current density is low, following Schottky emission.