Phys. Rev. B 76, 212101 (2007) [4 pages]Symmetry lowering under high pressure: Structural evidence for f-shell delocalization in heavy rare earth metal terbiumReceived 11 July 2007; revised 19 August 2007; published 10 December 2007 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 URL:
http://link.aps.org/doi/10.1103/PhysRevB.76.212101
DOI:
10.1103/PhysRevB.76.212101
PACS:
62.50.+p, 64.70.Kb, 64.30.+t, 71.20.Eh
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.