Exploring novel double perovskite SrEuTiFeO6: Synthesis, microstructural, optical, and dielectric properties

The novel double perovskite oxide SrEuTiFeO₆ was synthesized using the solid-state reaction method. X-ray diffraction analysis, complemented by Rietveld refinement, confirmed that this material crystallizes in a cubic double perovskite structure with the Pm3̅m space group and revealed cationic disorder at both the A (Sr, Eu) and B (Ti, Fe) sites. Crystallite size and lattice strain were determined through various methods. Fourier-transform infrared spectroscopy was utilized to examine vibrational modes and bond distortions within this material. Scanning electron microscopy showed a heterogeneous microstructure, with a wide distribution of grain sizes and shapes, resulting from the kinetics of the solid-state synthesis. Energy dispersive X-ray spectroscopy confirmed the material's homogeneity, stoichiometry, and chemical composition. UV–visible spectroscopy was used to investigate the optical properties of SrEuTiFeO₆, identifying several characteristic optical transitions. The band gap energy and refractive index were found to be 2.08 eV and 2.60, respectively, indicating the material's potential for various applications. Additionally, the dielectric properties, including the relative dielectric constant and loss tangent, were thoroughly analyzed as functions of frequency and temperature. The electrical conductivity dispersion phenomenon was also analyzed according to Jonscher's power law, revealing the predominance of overlapping the large polaron tunneling mechanism.