Exploration of the structural, optical, and dielectric performance of Mg-doped Sr2FeNbO6 double perovskite for wireless applications
Asif Ullah, Farman Ullah, Kamran Ullah, Fida Rehman, Aiyeshah Alhodaib, Salhah Hamed Alrefaee, Shaxnoza Saydaxmetova, Salah Knani, Vineet Tirth, Ali Algahtani, Abid Zaman
Abstract
This study examined the effects of Mg doping on the structural, optical, photoluminescence, and dielectric properties of a series of double perovskite Sr 2-x MgₓFeNbO₆ (0.00 ≤ x ≤ 0.40) ceramics that is successfully manufactured by using the mixed oxide route. It was proven by X-ray diffraction that a single-phase monoclinic perovskite (space group P21/c.) had formed, and at increasing Mg concentrations, SEM showed reduced porosity and increased grain uniformity. Tauc analysis and UV–Vis spectroscopy revealed a consistent decrease of the bandgap from 2.77 eV to 2.46 eV, which was ascribed to defect-induced electronic states and lattice distortion. The presence of levels of recombination-active defects was further confirmed by photoluminescence spectra. At high temperatures (~560 °C), dielectric studies revealed a low loss (tanδ = 2.0) and a high dielectric constant (εᵣ ≈800), which made these materials attractive options for wireless communication components. Mg-doped Sr₂FeNbO₆ ceramics have the potential for advanced applications in microwave electronics and optoelectronics due to their superior dielectric behavior, bandgap tunability, and integrated structural stability.