Structural investigations of sol-gel-derived LiYF{sub 4} and LiGdF{sub 4} powders

Journal Article · Thu Nov 15 00:00:00 EST 2007 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.09.008· OSTI ID:21043725

Lepoutre, S ^[1]; Potdevin, A; Dubois, M ^[1]; Briois, V ^[2]; Mahiou, R ^[1]

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1. Laboratoire des Materiaux Inorganiques, CNRS UMR 6002, Universite Blaise Pascal et Ecole Nationale Superieure de Chimie de Clermont-Ferrand, 24 Avenue des Landais, 63177 Aubiere cedex (France)
2. Synchrotron SOLEIL, L'Orme des Merisiers, BP48, 91192 Gif-sur-Yvette Cedex (France)

A soft synthesis route based on the sol-gel process was used for preparing rare-earth tetrafluoride powders from alkoxide precursors. In-situ fluorination was performed by decomposition of a fluorine containing organic compound named 1,1,1-trifluoro-5-methyl-2,4-hexanedione when sintering the as-prepared xerogel to produce crystallized samples. Both to insure complete departure of organic residues as well as to avoid any oxidation into oxyfluoride, annealing treatment was carried out under fluorine atmosphere. Free-oxygen content of resulting samples was evidenced by infrared and Raman spectroscopies. X-ray absorption spectroscopies (XAS) and {sup 19}F nuclear magnetic resonance (NMR) studies showed that samples heat treated at 300 deg. C are already crystallized but for a full crystallization in LiGdF{sub 4} and LiYF{sub 4} a thermal treatment at 550 deg. C is needed. Temperature dependence of powder morphology was analyzed by scanning electron microscopy (SEM). - Graphical abstract: The sol-gel route is a soft process, which allows developing versatile-shaped compounds. A fluorine organic compound named 1,1,1-trifluoro-5-methyl-2,4-hexadione was used to synthesis LiGdF{sub 4} and LiYF{sub 4} powders based on the sol-gel method. These materials can be used as host lattices for rare-earth ions to provide phosphors.

• OSTI ID: 21043725
• Journal Information: Journal of Solid State Chemistry, Vol. 180, Issue 11; Other Information: DOI: 10.1016/j.jssc.2007.09.008; PII: S0022-4596(07)00378-7; Copyright (c) 2007 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

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
ALKOXIDES
ANNEALING
CRYSTALLIZATION
DECOMPOSITION
FLUORINATION
GADOLINIUM FLUORIDES
LITHIUM FLUORIDES
NUCLEAR MAGNETIC RESONANCE
ORGANIC FLUORINE COMPOUNDS
OXIDATION
OXYFLUORIDES
POWDERS
RAMAN SPECTROSCOPY
SCANNING ELECTRON MICROSCOPY
SINTERING
SOL-GEL PROCESS
SYNTHESIS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K
X-RAY SPECTROSCOPY
YTTRIUM FLUORIDES