Effect of local structure of Sm3+ in MgAl2O4:Sm3+ phosphors prepared by thermal decomposition of triethanolamine complexes on their luminescence property
| Autor: | Thanawat Rimpongpisarn, Worawut Nantharak, Apirat Laobuthee, Worawat Wattanathana, Nattamon Koonsaeng, Chatchai Veranitisagul, Wantana Klysubun |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Extended X-ray absorption fine structure Dopant Mechanical Engineering Thermal decomposition Metals and Alloys Analytical chemistry Mineralogy chemistry.chemical_element Phosphor 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences XANES law.invention Samarium chemistry Mechanics of Materials law 0103 physical sciences Materials Chemistry Calcination 0210 nano-technology Luminescence |
| Zdroj: | Journal of Alloys and Compounds. 701:1019-1026 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2017.01.090 |
| Popis: | Samarium doped magnesium aluminate phosphors were successfully synthesized from a facile metal-triethanolamine complex method. The powders were obtained from calcining the metal complexes at various temperatures (800–1200 °C). Functional groups of the complexes and the calcined powders were determined by FT-IR. According to XRD patterns, no crystalline impurities were observed in the synthetic products. Morphology of the calcined products was studied by FE-SEM and TEM. The SEM and TEM results showed that the raising of calcination temperature enlarged the particle sizes of samarium doped magnesium aluminate due to particle agglomeration at high temperature. The prepared phosphors showed the characteristic photoemission peaks at 565, 602, 648 and 738 nm. XANES study revealed that the samarium dopant was in the valency state of 3+. Therefore, the luminescent peaks can be identified as the electronic transitions from the excited state 4G5/2 to 6H11/2, 6H9/2, 6H7/2, 6H5/2 levels, respectively. Interestingly, the calcination at 800 °C leaded to the most intense luminescence signal. From the EXAFS analysis, the local structure of Sm3+ from the sample obtained at 800 °C was not crystalline as only the first coordination shell was observed. The local structure of Sm3+ for samples calcined at other temperatures showed higher coordination shells. It can be concluded from the present work that Sm3+ in the environment of low periodicity exhibited a stronger luminescence. Furthermore, it was found that the optimum Sm3+ content for this series of phosphors was 1%. |
| Databáze: | OpenAIRE |
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