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.
@article{arxiv.1005.0262,
title = {High-pressure structural phase transitions in CuWO4},
author = {J. Ruiz-Fuertes and D. Errandonea and R. Lacomba-Perales and A. Segura and J. Gonzalez and F. Rodriguez and F. J. Manjon and S. Ray and P. Rodriguez-Hernandez and A. Munoz and Zh. Zhu and C. Y. Tu},
journal= {arXiv preprint arXiv:1005.0262},
year = {2010}
}