Microstructural characteristics and photoluminescence performance of nanograined thermally treated CeO2-TiO2 xerogels
Autor: | Harish Chander, Amita Verma, N. Karar, S.A. Agnihotry, Avanish Kumar Srivastava |
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Rok vydání: | 2007 |
Předmět: |
Photoluminescence
Materials science Scanning electron microscope Mechanical Engineering chemistry.chemical_element Condensed Matter Physics Nanocrystalline material Cerium chemistry Chemical engineering Mechanics of Materials Transmission electron microscopy General Materials Science Crystallite Composite material Luminescence Sol-gel |
Zdroj: | Journal of Materials Research. 22:1182-1187 |
ISSN: | 2044-5326 0884-2914 |
Popis: | Nanostructured thermally treated xerogels have been synthesized using a sol-gel process involving cerium (Ce) chloride heptahydrate and titanium (Ti) propoxide mixed in different Ce:Ti molar ratios. Structural features of the xerogels have been correlated with their photoluminescence (PL) response. The crystallite sizes in the samples lie in the nanorange. The x-ray diffraction and transmission electron microscopy results have confirmed the coexistence of CeO2 and TiO2 nanocrystallites in these xerogels. In general, a decrease in the CeO2 crystallite size and an increase in the TiO2 crystallite size are observed in the xerogels as a function of Ti content. Scanning electron microscopy results have evidenced the evolution of ordered structure in the xerogels as a function of TiO2 content. Although both of the phases (CeO2 and TiO2) have exhibited PL in ultraviolet and visible regions, the major luminescence contribution has been made by the CeO2 phase. The largest sized CeO2 crystallites in 1:1 thermally treated xerogel have led to its highest PL response. PL emission in the xerogels is assigned to their nanocrystalline nature and oxygen vacancy-related defects. |
Databáze: | OpenAIRE |
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