Structural and optical properties of A2YVO6 (A = Mg, Sr) double perovskite oxides

Abstract

New double perovskite oxides A2YVO6 (A = Mg, Sr) were prepared and synthesized using conventional methods via a solid-state reaction route. The samples were studied by X-ray powder diffraction (XRD) and the prepared Mg2YVO6 and Sr2YVO6 samples were shown to have monoclinic crystal structures belonging to the (P2/m) space group. The crystallite size in the samples was found to decrease from 56.320 to 40.480 nm upon increasing the A-site ionic radius. Scanning electron microscopy (SEM) results demonstrated that the sample microstructure consisted of homogenous crystallites of approximately 6.5-µm in size, and energy-dispersive X-ray (EDX) results revealed elements ratios in samples that were identical to the expected values. FTIR results allowed the identification of particular perovskite structural features from vibrational peaks in the range of 400–4000 cm−1, and optical structure in the range of 190–600 nm was obtained from ultraviolet–visible (UV–vis) spectroscopy. The identity of the element at the A site was found to affect the band-gap energy, which decreased from 2.9 to 2.4 eV with the change from Mg2YVO6 to Sr2YVO6, indicating that the A2YVO6 (A = Mg, Sr) samples may possess insulating characteristics.