Synthesis and spectral characteristics of Sr{sub 2}Y{sub 8}(SiO{sub 4}){sub 6}O{sub 2}: Eu polycrystals

Journal Article · Sat Jan 15 00:00:00 EST 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.10.014· OSTI ID:21494173

Karpov, A M ^[1]; Shkvarin, A S ^[2]

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1. Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation)
2. Institute of Metal Physics, Ural Branch of the Russian Academy of Sciences, 620041 Ekaterinburg (Russian Federation)

Spectral-luminescent characteristics of Sr{sub 2}Y{sub 8}(SiO{sub 4}){sub 6}O{sub 2}: Eu powder crystal phosphor with the apatite structure and high-intensity luminescence of Eu{sup 3+} ions have been studied. The charge state of europium in the samples has been characterized by means of X-ray L{sub 3}-adsorption spectroscopy. It was established that Eu{sup 3+} forms two types of optical centers. Besides, luminescence of Eu{sup 2+}ions was found. Reduction Eu{sup 3+}{yields}Eu{sup 2+} was considered, which may be due to V{sub Sr}{sup ||} vacancy formation in the 4f crystal lattice position and to negative charge transfer by this vacancy to two Eu{sub Y}{sup 3+} ions. Thus, in the silicate lattice there exist inhomogeneously distributed oxygen-deficient centers, which are responsible for nonradiative transfer of excitation energy to Eu{sup 3+} and Eu{sup 2+} ions. To study electron-vibrational interactions in the crystal phosphor samples, their IR and Raman spectra were examined. In the luminescence spectrum of Eu{sup 2+}, a series of low-intensity bands caused by interaction of the 4f{sup 6}5d state of Eu{sup 2+} with silicate lattice vibrations was observed. - Graphical abstract: The scheme of nonradiative transfer over of energy of excitation from oxygen vacancies to ions Eu{sup 2+} and Eu{sup 3+} in Sr{sub 2}Y{sub 8}(SiO{sub 4}){sub 6}O{sub 2}: Eu phosphors. Research Highlights: {yields}In Sr{sub 2}Y{sub 8}(SiO{sub 4}){sub 6}O{sub 2}:Eu phosphors optical centers Eu{sup 2+} and Eu{sup 3+} (two types) are formed. {yields}The 4f{sup 6}5d state of Eu{sup 2+} interacts with the lattice vibrations of Sr{sub 2}Y{sub 8}(SiO{sub 4}){sub 6}O{sub 2}:Eu. {yields}In crystal lattice Sr{sub 2}Y{sub 8} (SiO{sub 4})6O{sub 2}:Eu oxygen vacancies are formed. {yields}Oxygen vacancies nonradiatively transfer the energy of excitation to Eu{sup 2+} and Eu{sup 3+} ions. {yields}Oxygen vacancies are non-uniformly distributed in a phosphorus lattice.

• OSTI ID: 21494173
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 1; Other Information: DOI: 10.1016/j.jssc.2010.10.014; PII: S0022-4596(10)00468-8; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ADSORPTION
APATITES
CRYSTAL LATTICES
EUROPIUM
EUROPIUM IONS
EXCITATION
LATTICE VIBRATIONS
LUMINESCENCE
PHOSPHORS
POLYCRYSTALS
RAMAN SPECTRA
SPECTROSCOPY
STRONTIUM SILICATES
SYNTHESIS
VACANCIES
X-RAY DIFFRACTION
YTTRIUM SILICATES
ALKALINE EARTH METAL COMPOUNDS
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DIFFRACTION
ELEMENTS
EMISSION
ENERGY-LEVEL TRANSITIONS
IONS
METALS
MINERALS
OXYGEN COMPOUNDS
PHOSPHATE MINERALS
PHOTON EMISSION
POINT DEFECTS
RARE EARTHS
SCATTERING
SILICATES
SILICON COMPOUNDS
SORPTION
SPECTRA
STRONTIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS