Coupled commensurate charge density wave and lattice distortion in Na2Ti2Pn2 O (Pn=As,Sb) determined by x-ray diffraction and angle-resolved photoemission spectroscopy

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

8 Scopus Citations
View graph of relations

Author(s)

  • N. R. Davies
  • R. D. Johnson
  • A. J. Princep
  • L. A. Gannon
  • T. Qian
  • P. Richard
  • H. Li
  • M. Shi
  • H. Nowell
  • P. J. Baker
  • Y. G. Shi
  • H. Ding
  • J. Luo
  • Y. F. Guo
  • A. T. Boothroyd

Detail(s)

Original languageEnglish
Article number104515
Journal / PublicationPhysical Review B
Volume94
Issue number10
Publication statusPublished - 19 Sep 2016
Externally publishedYes

Abstract

We report single-crystal x-ray-diffraction measurements on Na2Ti2Pn2O(Pn=As,Sb) which reveal a charge superstructure that appears below the density wave transitions previously observed in bulk data. From symmetry-constrained structure refinements we establish that the associated distortion mode can be described by two propagation vectors q1=(1/2,0,l) and q2=(0,1/2,l) with l=0 (Sb) or l=1/2 (As) and primarily involves in-plane displacements of the Ti atoms perpendicular to the Ti-O bonds. We also present angle-resolved photoemission spectroscopy measurements, which show band folding and backbending consistent with a density wave with the same wave-vectors q1 and q2 associated with Fermi-surface nesting, and muon-spin relaxation data, which show no indication of spin density wave order. The results provide direct evidence for phonon-assisted charge density wave order in Na2Ti2Pn2O and fully characterize a proximate ordered phase that could compete with superconductivity in doped BaTi2Sb2O.

Bibliographic Note

Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to lbscholars@cityu.edu.hk.

Citation Format(s)

Coupled commensurate charge density wave and lattice distortion in Na2Ti2Pn2 O (Pn=As,Sb) determined by x-ray diffraction and angle-resolved photoemission spectroscopy. / Davies, N. R.; Johnson, R. D.; Princep, A. J.; Gannon, L. A.; Ma, J. Z.; Qian, T.; Richard, P.; Li, H.; Shi, M.; Nowell, H.; Baker, P. J.; Shi, Y. G.; Ding, H.; Luo, J.; Guo, Y. F.; Boothroyd, A. T.

In: Physical Review B, Vol. 94, No. 10, 104515, 19.09.2016.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review