Abstract
The effect of Sr
2+
substitution on the morphology, crystal structure, and optical properties of double perovskite oxide Ba
2−
x
Sr
x
ZnWO
6
(
x
= 0.00, 0.25, 0.50, 0.75, 1.00) were investigated. Scanning electronic microscopy demonstrated that all samples have similar microstructure morphology but differ in the range of grain sizes. X-ray diffraction measurements indicated that these materials crystallize in a (Fm-3m) cubic crystal structure, and also confirmed the tolerance factor. Rietveld analysis revealed that the lattice parameter decreased from 8.11834 to 8.039361 Å when the substitution of Ba
2+
with Sr
2+
cations increased from zero to 100%. Fourier transform infrared (FTIR) and Raman spectroscopies displayed a symmetric stretching vibration of WO
6
octahedra at 825 cm
−1
, and an anti-symmetric stretching mode of WO
6
was observed by FTIR at 620 cm
−1
. A strong peak at 420 cm
−1
was also observed in the Raman spectra and is due to the W–O–W bending vibration modes. UV-Vis diffuse reflectance spectroscopy was carried out for the series, and the band gap energy decreased from 3.27 eV for Ba
2
ZnWO
6
to 3.02 and 3.06 eV for Ba
1.75
Sr
0.25
ZnWO
6
and Ba
1.5
Sr
0.5
ZnWO
6
, respectively. The excitation and emission photoluminescence properties were investigated at room temperature.