Investigating structural, optoelectronic, and mechanical properties of novel Tungsten-based oxides double-perovskites compounds Sr2XWO6 (X= Mn, Fe): A DFT approach

Abstract

We employ PF-LAPW (full-potential linear augmented plane-wave) integrated within DFT (density functional theory) for a comprehensive exploration of the structural, optoelectronic, and mechanical properties of novel Tungsten-based oxides double-perovskites compounds Sr₂XWO₆ (X= Mn, Fe) through the quantum mechanical WIEN2K simulation package. All the computations are done by considering TB-mBJ (Tran-Blaha modified Becke-Johnson potential) and GGA (generalized gradient approximation) as the exchange-correlation potential. The stability and formation of the Sr₂XWO₆ (X= Mn, Fe) compounds in a cubic structure are validated through structural optimization and the tolerance factor. The analysis of elastic constants and Born-Huang stability criteria predict that the interested oxide double perovskites are ductile, mechanically stable, hard to scratch, anisotropic, and possess a dominant covalent bonding. Both Sr₂MnWO₆ and Sr₂FeWO₆ materials are indirect semiconductors with a band gap of 2.05 eV for Sr₂FeWO₆ and 1.98 eV for Sr₂MnWO₆ from W-L symmetry points within the 1st Brillouin zone. The small values of band gap and various parameters of optical properties, specifically the broad monotonically increasing absorption spectra, reveal that novel Tungsten-based oxides double-perovskites compounds Sr₂XWO₆ (X= Mn, Fe) exhibit great potential for optoelectronic properties.