| 1. |
- Spassky, Dmitry, et al.
(författare)
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Enhancement of light output in ScxY1-xPO4:Eu3+ solid solutions
- 2020
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Ingår i: Symmetry. - 2073-8994. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- The luminescence properties of ScxY1-xPO4:Eu3+ solid solutions have been studied under excitation by synchrotron radiation in the energy range of 4.5-50 eV. The luminescence originating from three different types of emission centers was observed, and the origin of the emission centers was determined. The light output of ScxY1-xPO4:Eu3+ was shown to depend non-linearly on the ratio of Sc and Y cations, whereas it is maximal in compounds with their equal content. The branching of the energy relaxation process between different emission centers is analyzed for the brightest Sc0.5Y0.5PO4:Eu3+ solid solution.
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| 2. |
- Spassky, Dmitry, et al.
(författare)
-
Influence of the Sc cation substituent on the structural properties and energy transfer processes in GAGG:Ce crystals
- 2020
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Ingår i: CrystEngComm. - : Royal Society of Chemistry (RSC). - 1466-8033. ; 22:15, s. 2621-2631
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Tidskriftsartikel (refereegranskat)abstract
- The influence of the Sc cation substituent on the structural and luminescence properties of GAGG:Ce crystals was studied. Unit cell parameters and space groups were obtained using XRD analysis. The chemical compositions of the crystals were determined using SEM-EDX and TEM-EDX techniques. Structures were refined by the Rietveld method and the distribution of Al/Ga/Sc cations between octahedral and tetrahedral sites was obtained. The influence of Sc on the electronic band structure and the energy of the 4f and 5d Ce3+ levels is shown. The modification of the band structure induced by the Sc electronic states results in the suppression of Gd emission and enhancement of Ce3+ emission at low temperatures. The Ce3+ emission decay is accelerated under high-energy excitation of the Sc-containing GAGG compound.
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| 3. |
- Spassky, Dmitry, et al.
(författare)
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Temperature dependent energy transfer to Eu3+ emission centres in K5Eu(MoO4)4 crystals
- 2024
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Ingår i: CrystEngComm. - 1466-8033. ; 26:8, s. 1106-1116
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Tidskriftsartikel (refereegranskat)abstract
- Luminescence properties of a palmierite-type K5Eu(MoO4)4 crystal were studied in a wide temperature range of 7-650 K. Eu3+ ions are shown to occupy at least three non-equivalent positions in the palmierite-type structure, forming emission centres with slightly different characteristics due to an incommensurate modulated disordering. The relative intensity of the Eu3+ emission bands originating from the 5D0 and 5D1 terms is shown to depend on excitation energy and the origin of the observed differences is discussed. It is shown that quenching temperature of the Eu3+ emission depends on excitation energy that is explained by energetical overlap of the 4f-4f Eu3+ transitions with the Urbach tail of the fundamental absorption region. Energy transfer processes to the Eu3+ emission centres were studied using the methods of time resolved spectroscopy.
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