Photoluminescence and EPR studies of Cr-doped hibonite (CaAl(12)O(19)) phosphors
IR@CGCRI: CSIR-Central Glass and Ceramic Research Institute, Kolkata
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| Title |
Photoluminescence and EPR studies of Cr-doped hibonite (CaAl(12)O(19)) phosphors
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| Creator |
Singh, Vijay
Chakradhar, R P S Rao, J. L. Kim, Dong-Kuk |
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| Subject |
Physical Properties
Glass |
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| Description |
CaAl(12)O(19):Cr powder phosphors have been prepared at 500 degrees C in less than 5 min by a combustion method and characterized by XRD, FT-IR, SEM, EPR and photoluminescence techniques. The g values evaluated from EPR spectroscopy indicate that the site symmetry around Cr(3+) ions is distorted octahedral as Cr(3+) ions substitute for Al(3+) sites. The number of spins (N) participating in the resonance for g = 1.97 is measured as a function of temperature and the activation energy is calculated. The paramagnetic susceptibility (chi) is calculated from the EPR data at various temperatures. From the plot 1/chi versus T, the Curie constant (C) and Curie paramagnetic temperature (theta(p)) have been evaluated. The exchange coupling constant J between Cr(3+) ions has also been evaluated. The excitation spectrum exhibits two broad bands characteristic of Cr(3+) ions in octahedral symmetry. The crystal field and Racah parameters have been evaluated and discussed. (c) 2008 Elsevier Masson SAS. All rights reserved.
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| Publisher |
Elsevier
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| Date |
2008-11
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://cgcri.csircentral.net/477/1/Solid_State_Sc_10_(2008)_1525%2D1532.pdf
Singh, Vijay and Chakradhar, R P S and Rao, J. L. and Kim, Dong-Kuk (2008) Photoluminescence and EPR studies of Cr-doped hibonite (CaAl(12)O(19)) phosphors. Solid State Sciences, 10 (11). pp. 1525-1532. ISSN 1293-2558 |
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| Relation |
http://cgcri.csircentral.net/477/
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