Structural, dielectric, electrical, and electronic-structure properties of Dy₀.₅Ba₀.₅CrO₃ perovskite

Abstract

Dy₀.₅Ba₀.₅CrO₃ was synthesized using a citrate-based sol–gel method and investigated through structural, microstructural, dielectric, impedance, electrical-transport, and electronic-structure analyses. X-ray diffraction and Rietveld refinement indicated the formation of a predominantly single-phase orthorhombic perovskite structure with Pnma symmetry. The refinement produced (R_p = 4.2%, R_wp = 5.6%, χ² = 2.17), and a goodness-of-fit value of 1.47. Williamson–Hall analysis gave an average crystallite size of approximately 44 nm and a microstrain of. The conductivity increased with temperature, confirming thermally activated semiconducting behavior. Activation energies of approximately eV for DC transport and eV for relaxation were obtained from Arrhenius analysis. The frequency-dependent conductivity followed Jonscher’s universal power law, while the impedance response exhibited thermally activated non-Debye relaxation and a decreasing overall resistance with increasing temperature. Because no equivalent-circuit fitting was performed, separate grain and grain-boundary parameters were not extracted. Oxygen-related defects and chromium mixed valence are discussed as possible contributors to localized transport but are not considered conclusively established without complementary bulk oxygen-stoichiometry measurements.