Advances in the structure and microstructure determination of yttrium silicates using the Rietveld method

Journal Article · Sun May 15 00:00:00 EDT 2005 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2005.02.024· OSTI ID:20725930

Cannas, Carla ^[1]; Musinu, Anna ^[1]; Piccaluga, Giorgio ^[1]; Deidda, Claudio ^[2]; Serra, Filomena ^[2]; Bazzoni, Marco ^[2]; Enzo, Stefano ^[2]

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1. Dipartimento di Scienze Chimiche, Cittadella Universitaria di Monserrato, S.S. 554 Bivio per Sestu, 09042 Cagliari (Italy)
2. Dipartimento di Chimica, via Vienna n. 2, 07100 Sassari (Italy)

The Y{sub 2}O{sub 3}-SiO{sub 2} 1:1 composition doped with a weak concentration of europium ions was prepared with the sol-gel technique and the products studied by X-ray diffraction as a function of temperature in the range from 900 to 1300 deg. C, using the method of Rietveld for quantitative evaluation of amorphous and crystalline evolving phases. The amorphous profile of the yttrium oxyorthosilicate glasses has been described following the 'Rietveld for Disordered Materials' method and subsequently included in the patterns of semicrystalline samples that have been heat-treated for temperatures above 900 deg. C at 1000, 1100, 1150, 1200 and 1300 deg. C. The quantitative evaluation of the amorphous phase is obtainable from the Rietveld approach equivalent to the method after Ruland. This enabled us to study in fine detail the structural rearrangements and growth mechanisms that take place during the crystal-to-amorphous transformation in terms of coordination numbers, average interatomic distances, average crystallite size and microstrain and to identify the polymorphous transformation involving the Y{sub 2}SiO{sub 5} phase from low-to-high-temperature forms, as well as some minor quantities of other phases namely {alpha}-Y{sub 2}Si{sub 2}O{sub 7} phase, Y{sub 2}O{sub 3} and Y{sub 4.67}(SiO{sub 4}){sub 3}O.

• OSTI ID: 20725930
• Journal Information: Journal of Solid State Chemistry, Vol. 178, Issue 5; Other Information: DOI: 10.1016/j.jssc.2005.02.024; PII: S0022-4596(05)00081-2; Copyright (c) 2005 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
AMORPHOUS STATE
CRYSTALS
DOPED MATERIALS
EUROPIUM IONS
HEAT TREATMENTS
INTERATOMIC DISTANCES
MICROSTRUCTURE
PHASE TRANSFORMATIONS
SILICON OXIDES
SOL-GEL PROCESS
SYNTHESIS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 1000-4000 K
X-RAY DIFFRACTION
YTTRIUM OXIDES
YTTRIUM SILICATES