Preparing, Characterizing, and Investigating Luminescent Properties of a Series of Long-Lasting Phosphors in a SrO–Al2O3 System: An Integrated and Inquiry-Based Experiment in Solid State Chemistry for the Undergraduate Laboratory
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[1] Peking University
Peking University
China
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 94, Nº 8, 2017, págs. 1157-1162
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
An integrated and inquiry-based experiment on solid state chemistry is applied to an inorganic chemistry lab course to provide insight into the characteristics of the solid phase reaction. In this experiment, students have the opportunity to synthesize long-lasting phosphors with formula xSrO·yAl2O3:Eu2+, Dy3+, by means of precipitation and high temperature methods, and to characterize them by powder X-ray diffractometry. The luminescent properties of the phosphors are also suitable for investigation by student research teams with the assistance of solid fluorescence analysis. With a change in the Sr/Al ratio of strontium aluminates, the phosphors show distinct emission bands, and with a change in the content of Dy in a certain range, the different data of luminescence intensity and decay time can be obtained. By analyzing the crystal structures and photoluminescence mechanism of products, students can better understand abstract concepts of luminescent solid materials, including nonstoichiometric compounds, extrinsic point defects, crystalline fields in the solid state, band levels, and hole and electron transfer.
