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arXiv · 1005.0262

High-pressure structural phase transitions in CuWO4

J. Ruiz-Fuertes·D. Errandonea·R. Lacomba-Perales·A. Segura·J. Gonzalez·F. Rodriguez·F. J. Manjon·S. Ray·P. Rodriguez-Hernandez·A. Munoz·Zh. Zhu·C. Y. Tu
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Abstract

We study the effects of pressure on the structural, vibrational, and magnetic behavior of cuproscheelite. We performed powder x-ray diffraction and Raman spectroscopy experiments up to 27 GPa as well as ab initio total-energy and lattice-dynamics calculations. Experiments provide evidence that a structural phase transition takes place at 10 GPa from the low-pressure triclinic phase (P-1) to a monoclinic wolframite-type structure (P2/c). Calculations confirmed this finding and indicate that the phase transformation involves a change in the magnetic order. In addition, the equation of state for the triclinic phase is determined: V0 = 132.8(2) A3, B0 = 139 (6) GPa and = 4. Furthermore, experiments under different stress conditions show that non-hydrostatic stresses induce a second phase transition at 17 GPa and reduce the compressibility of CuWO4, B0 = 171(6) GPa. The pressure dependence of all Raman modes of the triclinic and high-pressure phases is also reported and discussed.

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J. Ruiz-Fuertes, D. Errandonea, R. Lacomba-Perales, A. Segura, J. Gonzalez, F. Rodriguez, F. J. Manjon, S. Ray, P. Rodriguez-Hernandez, A. Munoz, Zh. Zhu, C. Y. Tu. 2010-05-03. High-pressure structural phase transitions in CuWO4. https://doi.org/10.1103/physrevb.81.224115

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