Pressure-induced iso-structural phase transition in CeO$_{2}$ above megabar pressures

ORAL

Abstract

The pressure-induced structural phase transition of cerium dioxide, CeO$_{2}$, has been studied by synchrotron angle X-ray diffraction technique using diamond anvil cell up to 175 GPa at room temperature. In addition to the \textit{Fm-3m} to \textit{pnma} structural phase transition at about 30 GPa, which was found previously, a \textit{pnma} to\textit{ pnma} iso-structural phase transition was found above megabar pressure range. During the phase transition, the $a$ axis of the unit cell collapses, while the $b$ and $c$ axis expand. However, abrupt change of the unit cell volume during the phase transition was not observed.

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Authors

  • Lei Liu

    • Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP

  • Wenge Yang

    • HPSynC, Geophysical Laboratory, Carnegie Institution of Washington

  • Hongxing Song

    • Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP

  • Huayun Geng

    • Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP

  • Yan Bi

    • Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP

  • Jian Xu

    • Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP