Polymorphism in yttrium molybdate Y{sub 2}Mo{sub 3}O{sub 12}
- Department of Chemistry, University of Toledo, Toledo, OH 43606 (United States)
Yttrium molybdate (Y{sub 2}Mo{sub 3}O{sub 12}) has been prepared by non-hydrolytic sol-gel chemistry. The phase evolution upon heating was investigated using in situ and ex situ heat treatments combined with powder X-ray diffraction. This method has led to the isolation of two orthorhombic phases with different atomic connectivity. Yttrium adopts 6- and 7-coordinate sites in the Pbcn and Pba2 structures, respectively. Cocrystallization of both phases was observed in a narrow temperature range, suggesting that crystallization kinetics play a major role in phase formation. It was found that the Pba2 phase is the stable polymorph below 550 deg. C, and converts to Pbcn at higher temperatures. - Graphical abstract: Yttrium molybdate (Y{sub 2}Mo{sub 3}O{sub 12}) prepared by non-hydrolytic sol-gel chemistry crystallizes in a mixture of orthorhombic polymorphs with different atomic connectivities. The Pbcn and Pba2 phases coexist over a narrow temperature range. Crystallization of the Pbcn structure is kinetically favored. The Pba2 polymorph is the thermodynamically stable phase at low temperatures, and converts to Pbcn above 550 deg. C.
- OSTI ID:
- 21043781
- Journal Information:
- Journal of Solid State Chemistry, Vol. 180, Issue 12; Other Information: DOI: 10.1016/j.jssc.2007.10.011; PII: S0022-4596(07)00424-0; 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
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