Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Surface structure and stacking of the commensurate (√13×√13)R13.9 charge density wave phase of 1T−TaS2(0001)


Ropers,  Claus       
Department of Ultrafast Dynamics, MPI for Biophysical Chemistry, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)

(Preprint), 5MB

Supplementary Material (public)
There is no public supplementary material available

Von Witte, G., Kißlinger, T., Horstmann, J., Rossnagel, K., Schneider, M., Ropers, C., et al. (2019). Surface structure and stacking of the commensurate (√13×√13)R13.9 charge density wave phase of 1T−TaS2(0001). Physical Review B, 100(15): 155407. doi:10.1103/PhysRevB.100.155407.

Cite as: https://hdl.handle.net/21.11116/0000-000B-5E33-3
By quantitative low-energy electron diffraction (LEED) we investigate the extensively studied commensurate charge density wave (CDW) phase of trigonal tantalum disulphide (1T−TaS2), which develops at low temperatures with a (√13×√13)R13.9∘ periodicity. A full-dynamical analysis of the energy dependence of diffraction spot intensities reveals the entire crystallographic surface structure, i.e., the detailed atomic positions within the outermost two trilayers consisting of 78 atoms as well as the CDW stacking. The analysis is based on an unusually large data set consisting of spectra for 128 inequivalent beams taken in the energy range 20–250 eV and an excellent fit quality expressed by a best-fit Pendry R factor of R=0.110. The LEED intensity analysis reveals that the well-accepted model of star-of-David-shaped clusters of Ta atoms for the bulk structure also holds for the outermost two TaS2 trilayers. Specifically, in both layers the clusters of Ta atoms contract laterally by up to 0.25 Å and also slightly rotate within the superstructure cell, causing respective distortions as well as heavy bucklings (up to 0.23 Å) in the adjacent sulfur layers. Most importantly, our analysis finds that the CDWs of the first and second trilayers are vertically aligned, while there is a lateral shift of two units of the basic hexagonal lattice (6.71 Å) between the second and third trilayers. The results may contribute to a better understanding of the intricate electronic structure of the reference compound 1T−TaS2 and guide the way to the analysis of complex structures in similar quantum materials.