Molten salt synthesis, structural and photoluminescence properties of $\mathbf{S}\mathbf{r}\mathbf{B}{\mathbf{i}}_{0.95}\mathbf{S}{\mathbf{m}}_{0.05}\mathbf{T}{\mathbf{a}}_{2-{\varvec{x}}}{\mathbf{V}}_{{\varvec{x}}}{\mathbf{O}}_{9}$ ($0\le {\varvec{x}}\le 0.2$)

Abstract

${\mathrm{SrBi}}_{0.95}{\mathrm{Sm}}_{0.05}{\mathrm{Ta}}_{2-x}{\mathrm{V}}_{x}{\mathrm{O}}_{9}$ (x = 0, 0.05, 0.1, 0.2) compounds, which have been studied through X-ray diffraction Rietveld refinement, Fourier transform infrared (FTIR), absorption and emission techniques, were prepared through the molten salt method. All samples were refined in the orthorhombic system without any secondary phase detected. The Ta–O bond strength in the compounds is revealed by FTIR and Rietveld measurements. Along with scanning electron microscopic analysis, ceramics also consist of plate-like grains that decreased with the V content increasing. The difference in absorption spectra is attributed to localized tail stats within the bandgap. According to the impedance and AC conductivity results, after introducing vanadium into the structure, the V-doped ${\mathrm{SrBi}}_{0.95}{\mathrm{Sm}}_{0.05}{\mathrm{Ta}}_{2}{\mathrm{O}}_{9}$ ceramics exhibit higher conductivity. The reason that x = 0.1 ceramic has the smallest semicircle radius referring to a higher efficient charge carrier transfer is that this ceramic sample is mainly composed of large particles. Samarium emits orange-red colour at wavelength 599 nm, which is attributed to ${}^{4}\mathrm{G}_{\frac{5}{2}}\to { }^{6}\mathrm{H}_{\frac{7}{2}}$ transition. Regarding photoluminescence intensity, the more vanadium ions are introduced into the lattice, the fewer emission peaks are obtained. The latter has been interpreted in terms of the inhibition of the transfer of energy from one ion to another. In essence, The red photoluminescence emission intensity of Sm ${}^{3+}$ ions were successfully enhanced in ${\mathrm{SrBi}}_{0.95}{\mathrm{Sm}}_{0.05}{\mathrm{Ta}}_{2-x}{\mathrm{V}}_{x}{\mathrm{O}}_{9}$ (x = 0.05).