High-Pressure X-Ray Diffraction Study of Scheelite-type Perrhenates
Universidad de Valencia（瓦伦西亚大学）；CELLS-ALBA Synchrotron Light Facility（CELLS-ALBA同步辐射光源设施）；Elettra Sincrotrone Trieste（的里雅斯特电子同步加速器）；University of Hyderabad（海德拉巴大学）；Universidad de La Laguna（拉古纳大学）；The University of Sydney（悉尼大学）
Neha Bura, Pablo Botella, Catalin Popescu, Frederico Alabarse, Ganapathy Vaitheeswaran, Alfonso Munoz, Brendan J. Kennedy, Jose Luis Rodrigo Ramon, Josu Sanchez… 展开作者
Neha Bura, Pablo Botella, Catalin Popescu, Frederico Alabarse, Ganapathy Vaitheeswaran, Alfonso Munoz, Brendan J. Kennedy, Jose Luis Rodrigo Ramon, Josu Sanchez-Martin, Daniel Errandonea
备注：
32 pages, 9 figures, 6 tables, 44 references
发表信息：
Journal of Physical Chemistry C 2025, 129, 35, 15865-15877
The effects of pressure on the crystal structure of scheelite-type perrhenates were studied using synchrotron powder X-ray diffraction and density-functional theory. At ambient conditions, the studied materials AgReO4, KReO4, and RbReO4, exhibit a tetragonal scheelite-type crystal structure described by space group I41/a. Under compression, a transition from scheelite-to-M${\prime}$-fergusonite (space group P21/c) was observed at 1.6 and 7.4 GPa for RbReO4 and KReO4, respectively. The transition involves a relative volume decrease. On the other hand, AgReO4 underwent a phase transition to the M-fergusonite structure (space group I2/a) at 13.6 GPa. In this case there is no appreciable volume discontinuity. The room-temperature pressure-volume equation of state for the three studied perrhenates was estimated using a second-order Birch-Murnaghan equation of state. The results for the low-pressure phase are confirmed by density-functional theory calculations. The analysis of the bulk modulus shows that the compressibility of the compounds decreases following the sequence RbReO4 > KReO4 > AgReO4, which is related to the compressibility of the RbO8, KO8, and AgO8 bidisphenoid units. Density-functional theory also offers valuable insights into the elastic constants. Despite giving a good description for the low-pressure phase in the three compounds, density-functional theory cannot catch the structural phase transition observed in experiments. Reasons for it are discussed in the manuscript.
