A high-pressure Raman study of KReO4, RbReO4 and CsReO4 to 25 GPa and pressure-induced phase transitions

Jayaraman, A. ; Kourouklis, G. A. ; van Uitert, L. G. ; Grodkiewicz, W. H. ; Maines, R. G. (1989) A high-pressure Raman study of KReO4, RbReO4 and CsReO4 to 25 GPa and pressure-induced phase transitions Physica A: Statistical Mechanics and Its Applications, 156 (1). pp. 325-340. ISSN 0378-4371

Full text not available from this repository.

Official URL: http://www.sciencedirect.com/science/article/pii/0...

Related URL: http://dx.doi.org/10.1016/0378-4371(89)90126-X

Abstract

The pressure dependence of the Raman spectrum of KReO4, RbReO4 and CsReO4 has been investigated to 25 GPa using the diamond anvil cell. From the changes in the Raman spectra the occurrence of three pressure-induced phase transitions in KReO4 and RbReO4 and two transitions in CsReO4 have been deduced. These transitions are found to occur at 7.5, 10 and 14 GPa in KReO4, 1.6, 5.5 and 15 GPa in RbReO4, and at 10 and 14 GPa in the case of CsReO4. The transition sequence with increasing pressure seems to be from scheelite→pseudoscheelite→wolframite→denser complex structure. These changes would involve a change in the structure from a tetragonal→orthorhombic→monoclinic→triclinic lattice, with increases in density at each transition. No drastic change in the optical absorption occurs in these alkali rehenates up to 25 GPa, the highest pressure to which these materials were investigated. This is in contrast with the behavior of TIReO4 which turns black at the third pressure-induced phase transition near 10 GPa presumably due to a change in the valence state of Tl from +1 to the +3 state.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
ID Code:96086
Deposited On:04 Dec 2012 09:57
Last Modified:04 Dec 2012 09:57

Repository Staff Only: item control page