1. UV–vis absorption shift of mixed valance state tungstate oxide: Ca0.72La0.28WO4.
- Author
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Yuan, Long, Yu, Jing, Wang, Shan, Huang, Keke, Ren, Xiaoru, Sun, Yu, Wu, Xiaofeng, and Feng, Shouhua
- Subjects
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TUNGSTEN oxides , *ULTRAVIOLET radiation , *ABSORPTION , *HYDROTHERMAL synthesis , *X-ray diffraction , *SCANNING electron microscopy - Abstract
CaWO 4 and Ca 0.72 La 0.28 WO 4 samples were synthesized via mild hydrothermal method at 180 °C. Composition, phase purity, morphology and W element binding energy were characterized by induced couple plasma atomic emission spectrum (ICP-AES), powder x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray energy dispersive spectroscopy (EDS), and x-ray photoelectron spectroscopy (XPS). UV–vis absorption spectroscopy shows absorption peak shift due to La 3+ doping, which induced to the presence of mixed valence states of W 5+ and W 6+ in scheelite-type structure compound. Hence, blue shift of UV–vis absorption from 350 nm to 405 nm was observed in La 3+ -doped calcium tungstate. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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