Spectral characteristics of nanoamorphous phosphors obtained by evaporation of Sr{sub 2}Gd{sub 8}(SiO{sub 4}){sub 6}O{sub 2}: Eu polycrystals
- Institute of Electrophysics, Ural Branch of the Russian Academy of Sciences, 620216 Ekaterinburg (Russian Federation)
- Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation)
Amorphous nanophosphors have been obtained for the first time by pulsed electron beam evaporation of targets from bulk polycrystalline phosphors of the composition Sr{sub 2}Gd{sub 8}(SiO{sub 4}){sub 6}O{sub 2}: Eu with oxyapatite structure. The processes of crystallization of amorphous nanopowder were studied using differential scanning calorimetry and termogravimetry (40−1400 °C). It was found that the Raman spectra of the samples are modified when the particles decrease from bulk to nanodimensional state. The spectral and luminescent characteristics of the phosphors in polycrystalline and nanoamorphous states have been examined. It was established that Eu{sup 3+} forms two types of optical centers. Unlike bulk phosphors, in the nanophosphors no Eu{sup 2+} ions are formed. The ratio of red to orange luminescence intensity for nanophosphors was found to increase as compared with bulk phosphors. This effect is due to disordering of nanoparticles. A resonant transfer of excitation energy from Gd{sup 3+} to Eu{sup 3+} ions was found in bulk and nanophosphors. Upon transition from polycrystalline to nanoamorphous state and laser excitation of phosphors, the luminescence intensity of Eu{sup 3+} ions increases approximately 10 times. This effect is explained in the framework of the configuration coordinates model. - Graphical abstract: Schematic configurational-coordinate diagram for Eu{sup 3+} ion in polycrystalline Sr{sub 2}Gd{sub 6.4}Eu{sub 1.6}Si{sub 6}O{sub 26−δ} and nanoamorphous phosphor. - Highlights: • Nanoamorphous phosphor is obtained by electron-beam evaporation of bulk silicate. • In nanoamorphous samples Raman spectra are modified intensity. • Nanofosfor luminescence by 10 times more intensively, than bulk phosphorus. • There is a transfer of energy of excitation from Gd{sup 3+} to Eu{sup 3+} in bulk- and nanophosphor.
- OSTI ID:
- 22443425
- Journal Information:
- Journal of Solid State Chemistry, Vol. 218; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
Similar Records
Synthesis and spectral characteristics of Sr{sub 2}Y{sub 8}(SiO{sub 4}){sub 6}O{sub 2}: Eu polycrystals
Properties of Gd{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} nanopowders obtained by sol-gel process