Charge Density Wave and Narrow Energy Gap at Room Temperature in 2D Pb3-xSb1+xS4Te2-δ with Square Te Sheets

Haijie Chen, Christos D. Malliakas, Awadhesh Narayan, Lei Fang, Duck Young Chung, Lucas K. Wagner, Wai Kwong Kwok, Mercouri G Kanatzidis

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

We report a new two-dimensional compound, Pb3-xSb1+xS4Te2-δ, that has a charge density wave (CDW) at room temperature. The CDW is incommensurate with q-vector of 0.248(6)a∗ + 0.246(8)b∗ + 0.387(9)c∗ for x = 0.29(2) and δ = 0.37(3) due to positional and occupational long-range ordering of Te atoms in the sheets. The modulated structure was refined from the single-crystal X-ray diffraction data with a superspace group P1(αβγ)0 using (3 + 1)-dimensional crystallography. The resistivity increases with decreasing temperature, suggesting semiconducting behavior. The transition temperature (TCDW) of the CDW is ∼345 K, above which the Te square sheets become disordered with no q-vector. First-principles density functional theory calculations on the undistorted structure and an approximate commensurate supercell reveal that the gap is due to the structure modulation.

Original languageEnglish
Pages (from-to)11271-11276
Number of pages6
JournalJournal of the American Chemical Society
Volume139
Issue number32
DOIs
Publication statusPublished - Aug 16 2017

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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