Jayaraman, A. ; Kourouklis, G. A. ; Espinosa, G. P. ; Cooper, A. S. ; Van Uitert, L. G. (1987) A high-pressure Raman study of yttrium vanadate (YVO4) and the pressure-induced transition from the zircon-type to the scheelite-type structure Journal of Physics and Chemistry of Solids, 48 (8). pp. 755-759. ISSN 0022-3697
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Official URL: http://www.sciencedirect.com/science/article/pii/0...
Related URL: http://dx.doi.org/10.1016/0022-3697(87)90072-2
Abstract
The pressure dependences of the Raman active modes in yttrium vanadate (YVO4) crystallizing in the zircon-type structure D4h19 (I41/amd), have been studied using a diamond anvil cell up to 15 GPa. At room temperature the zircon-type structure transforms to the scheelite-type structure C4h6(I41/a) with a = 5.04 Å and c = 11.24 Å near 7.5 GPa. The density changes from 4.24 to 4.74 g/cm3 in the transition, and the corresponding volume decrease is ΔV = 5.07 cm3/mole. The high-pressure phase is retained on release of pressure. The optical absorption edge shifts from 3.87 to 2.77 eV at the transition, presumably due to charge transfer, or due to V-O bond length change of the VO4 tetrahedra. The internal mode frequencies of the VO4 tetrahedra also decrease abruptly at the transition. The V-O bond stretching frequency decreases from 891 to 828 cm−1 in the scheelite-type phase, which suggests a fundamental change in the VO4 unit. The general question of the stability of the zircon-type structure under high pressure is discussed in the light of the high-pressure behavior of a large number of rare earth vanadates and arsenates.
Item Type: | Article |
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Source: | Copyright of this article belongs to Elsevier Science. |
ID Code: | 96076 |
Deposited On: | 04 Dec 2012 10:20 |
Last Modified: | 04 Dec 2012 10:20 |
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