Symmetry lowering under high pressure: Structural evidence for f -shell delocalization in heavy rare earth metal terbium

Academic Article


  • Heavy rare earth metal terbium has been studied at synchrotron sources using both angular and energy dispersive x-ray diffraction to a maximum pressure of 155 GPa (volume fraction V/ V0 =0.39). The complete regular trivalent rare earth structural sequence, hcp→α-Sm→double hcp→fcc→ distorted fcc (hR24), is observed at low pressures except for the undistorted fcc. At 51±2 GPa, terbium undergoes a 5% volume collapse transitioning to C2/m monoclinic. The open, low symmetry structure is reminiscent of the 4f delocalization phenomenon in the light rare earth metals, particularly the α″ phase of cerium. © 2007 The American Physical Society.
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Cunningham NC; Qiu W; Hope KM; Liermann HP; Vohra YK
  • Volume

  • 76
  • Issue

  • 21