Correlated local dipoles in PbTe

Boris Sangiorgio, Emil S. Bozin, Christos D. Malliakas, Michael Fechner, Arkadiy Simonov, Mercouri G Kanatzidis, Simon J.L. Billinge, Nicola A. Spaldin, Thomas Weber

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We present a combined single-crystal x-ray diffuse scattering and ab initio molecular dynamics study of lead telluride, PbTe. Well-known for its thermoelectric and narrow-gap semiconducting properties, PbTe recently achieved further notoriety following the report of an unusual off-centering of the lead atoms, accompanied by a local symmetry breaking, on heating. This observation, which was named emphanisis, ignited considerable controversy regarding the details of the underlying local structure and the appropriate interpretation of the total scattering experiments. In this study, we identify an unusual correlated local dipole formation extending over several unit cells with an associated local reduction of the cubic symmetry in both our x-ray diffuse scattering measurements and our molecular dynamics simulations. Importantly, when averaged spatially or temporally, the most probable positions for the ions are at the centers of their coordination polyhedra. Our results therefore clarify the nature of the local symmetry breaking, and reveal the source of the earlier controversy regarding the existence or absence of off-centering. Finally, we provide an interpretation of the behavior in terms of coupled soft optical and acoustic modes which is linked also to the high thermoelectric performance of PbTe.

Original languageEnglish
Article number085402
JournalPhysical Review Materials
Volume2
Issue number8
DOIs
Publication statusPublished - Aug 6 2018

Fingerprint

Scattering
dipoles
Molecular dynamics
broken symmetry
scattering
lead tellurides
molecular dynamics
X rays
polyhedrons
x rays
Lead
Single crystals
Ions
Heating
Atoms
heating
acoustics
single crystals
Computer simulation
symmetry

ASJC Scopus subject areas

  • Materials Science(all)
  • Physics and Astronomy (miscellaneous)

Cite this

Sangiorgio, B., Bozin, E. S., Malliakas, C. D., Fechner, M., Simonov, A., Kanatzidis, M. G., ... Weber, T. (2018). Correlated local dipoles in PbTe. Physical Review Materials, 2(8), [085402]. https://doi.org/10.1103/PhysRevMaterials.2.085402

Correlated local dipoles in PbTe. / Sangiorgio, Boris; Bozin, Emil S.; Malliakas, Christos D.; Fechner, Michael; Simonov, Arkadiy; Kanatzidis, Mercouri G; Billinge, Simon J.L.; Spaldin, Nicola A.; Weber, Thomas.

In: Physical Review Materials, Vol. 2, No. 8, 085402, 06.08.2018.

Research output: Contribution to journalArticle

Sangiorgio, B, Bozin, ES, Malliakas, CD, Fechner, M, Simonov, A, Kanatzidis, MG, Billinge, SJL, Spaldin, NA & Weber, T 2018, 'Correlated local dipoles in PbTe', Physical Review Materials, vol. 2, no. 8, 085402. https://doi.org/10.1103/PhysRevMaterials.2.085402
Sangiorgio B, Bozin ES, Malliakas CD, Fechner M, Simonov A, Kanatzidis MG et al. Correlated local dipoles in PbTe. Physical Review Materials. 2018 Aug 6;2(8). 085402. https://doi.org/10.1103/PhysRevMaterials.2.085402
Sangiorgio, Boris ; Bozin, Emil S. ; Malliakas, Christos D. ; Fechner, Michael ; Simonov, Arkadiy ; Kanatzidis, Mercouri G ; Billinge, Simon J.L. ; Spaldin, Nicola A. ; Weber, Thomas. / Correlated local dipoles in PbTe. In: Physical Review Materials. 2018 ; Vol. 2, No. 8.
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