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Author Novais, S. M. V. ♦ Macedo, Z. S.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY ♦ ABSORPTION SPECTROSCOPY ♦ CERIUM IONS ♦ DOPED MATERIALS ♦ EUROPIUM IONS ♦ EXCITATION ♦ INTERATOMIC DISTANCES ♦ LATTICE PARAMETERS ♦ LUMINESCENCE ♦ MONOCLINIC LATTICES ♦ OXYGEN ♦ OXYGEN IONS ♦ PEAKS ♦ PHOSPHATES ♦ RARE EARTHS ♦ SCINTILLATIONS ♦ SOL-GEL PROCESS ♦ SOLS ♦ X RADIATION ♦ X-RAY SPECTROSCOPY ♦ YTTRIUM IONS
Abstract Direct determination of rare earth location and local environment in NaYP{sub 2}O{sub 7} are presented. Undoped and Ln-doped NaYP{sub 2}O{sub 7} (Ln=Eu, Ce) were produced via PVA-assisted sol–gel method. Lattice parameters were determined from Rietveld refinement, showing monoclinic structure. XAS results suggested Eu{sup 3+} and Ce{sup 3+} are incorporated into NaYP{sub 2}O{sub 7} host in substitution to Y{sup 3+} site, with first coordination shell formed by six oxygen ions. Measurements at Eu edge showed a single peak in R space for Eu–O distribution. In this case, uniform interatomic distances implied to absence of significant disorder. Analysis at Ce edge presented different behavior, with Ce–O distribution characterized by a split peak in R space. Nearest neighborhood was found to be distributed with Ce occupying an off-center position in Y site. Under X-ray excitation, {sup 5}D{sub 0}→{sup 7}F{sub J} emission lines of Eu{sup 3+} were identified for NaYP{sub 2}O{sub 7}:Eu. NaYP{sub 2}O{sub 7}:Ce presented a broad emission formed by 5d→{sup 2}F{sub J} transitions of Ce{sup 3+}, with the superposition attributed to the effect of distorted oxygen octahedra around the dopant ions. - Graphical abstract: EuO{sub 6} and CeO{sub 6} octahedral arrangement relative to Y site in NaYP{sub 2}O{sub 7} host, and XEOL emission of corresponding doped samples. - Highlights: • Lattice parameters of NaYP{sub 2}O{sub 7} undoped sample confirmed monoclinic structure. • Dopants Eu and Ce are incorporated in the trivalent state. • Local order of Eu{sup 3+} and Ce{sup 3+} dopants substituting Y{sup 3+} consist of octahedral symmetry. • Off-center displacement in the case of Ce{sup 3+} position was discussed. • Luminescent properties under X-ray excitation may allow practical applications.
ISSN 00224596
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-01-15
Publisher Place United States
Journal Journal of Solid State Chemistry
Volume Number 233


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