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Author Tyagi, Adish ♦ Shah, Alpa ♦ Sudarsan, V. ♦ Vatsa, R. K. ♦ Jain, V. K.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY ♦ COLOR ♦ CONCENTRATION RATIO ♦ CRYSTALLOGRAPHY ♦ DOPED MATERIALS ♦ DYSPROSIUM ADDITIONS ♦ EXCITATION ♦ GERMANATES ♦ IMPURITIES ♦ ION PAIRS ♦ LUMINESCENCE ♦ MONOCLINIC LATTICES ♦ ORTHORHOMBIC LATTICES ♦ RELAXATION ♦ SYNTHESIS ♦ TERBIUM ADDITIONS ♦ ULTRAVIOLET RADIATION ♦ VISIBLE RADIATION ♦ X-RAY DIFFRACTION ♦ YTTRIUM COMPOUNDS
Abstract Highlights: • Improved emission colour purity with orthorhombic form of Y{sub 2}GeO{sub 5}. • Non-stationary quenching exists in orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5}:Tb. • Ion pair formation and cross relaxation quenching operating for Y{sub 2}GeO{sub 5}:Dy samples. - Abstract: The luminescence properties of Tb{sup 3+} and Dy{sup 3+} doped orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5} are significantly different. Orthorhombic Y{sub 2}GeO{sub 5} doped with Tb{sup 3+} and Dy{sup 3+} ions gives bright green and blue emission upon UV light excitation with CIE coordinates (0.25, 0.46) and (0.25, 0.24), respectively. The monoclinic Y{sub 2}GeO{sub 5} doped with these ions exhibits light green and yellowish white emissions, respectively. This has been attributed to the differences in crystallographic environments around Y{sup 3+} ions in orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5}. Quantum yield of emission for orthorhombic Y{sub 2}GeO{sub 5}:Tb (∼29%) is significantly higher than that of the monoclinic Y{sub 2}GeO{sub 5}:Tb (∼14%). Lifetime values corresponding to {sup 4}F{sub 9/2} level of Dy{sup 3+} ions in both monoclinic and orthorhombic forms of Y{sub 2}GeO{sub 5} follow an opposite trend with respect to {sup 5}D{sub 4} level of Tb{sup 3+} ions. This is attributed to difference in the concentration quenching mechanism operating for Tb{sup 3+} and Dy{sup 3+} ions.
ISSN 00255408
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-04-15
Publisher Place United States
Journal Materials Research Bulletin
Volume Number 64


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