Alsabah Yousef A, AlSalhi Mohamad S, Elbadawi Abdelrahman A, Mustafa Eltayeb M
Department of Physics, Faculty of Science and Technology, Al Neelain University, Khartoum 13314, Sudan.
Research Chair in Laser Diagnosis of Cancers, Department of Physics and Astronomy, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
Materials (Basel). 2017 Apr 28;10(5):469. doi: 10.3390/ma10050469.
The effect of Sr substitution on the morphology, crystal structure, and optical properties of double perovskite oxide BaSrZnWO₆ ( = 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 with Sr cations increased from zero to 100%. Fourier transform infrared (FTIR) and Raman spectroscopies displayed a symmetric stretching vibration of WO₆ octahedra at 825 cm, and an anti-symmetric stretching mode of WO₆ was observed by FTIR at 620 cm. A strong peak at 420 cm 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 Ba₂ZnWO₆ to 3.02 and 3.06 eV for BaSrZnWO₆ and BaSrZnWO₆, respectively. The excitation and emission photoluminescence properties were investigated at room temperature.
研究了 Sr 取代对双钙钛矿氧化物 BaSrZnWO₆（= 0.00、0.25、0.50、0.75、1.00）的形貌、晶体结构和光学性质的影响。扫描电子显微镜表明，所有样品具有相似的微观结构形貌，但晶粒尺寸范围不同。X 射线衍射测量表明，这些材料结晶为（Fm-3m）立方晶体结构，并证实了容差因子。Rietveld 分析表明，当 Sr 阳离子取代 Ba 的比例从零增加到 100%时，晶格参数从 8.11834 Å 减小到 8.039361 Å。傅里叶变换红外（FTIR）和拉曼光谱显示，WO₆ 八面体在 825 cm 处有对称伸缩振动，FTIR 在 620 cm 处观察到 WO₆ 的反对称伸缩模式。拉曼光谱中还在 420 cm 处观察到一个强峰，这归因于 W-O-W 弯曲振动模式。对该系列进行了紫外-可见漫反射光谱分析，带隙能量从 Ba₂ZnWO₆ 的 3.27 eV 分别降至 BaSrZnWO₆ 和 BaSrZnWO₆ 的 3.02 eV 和 3.06 eV。在室温下研究了激发和发射光致发光特性。
