Structure and thermoelectric properties of the new quaternary bismuth selenides A1-xM4-xBi11+xSe21 (A = K and Rb and Cs; M = Sn and Pb) members of the grand homologous series km(M6Se8)m(M5+nSe 9+n)

Antje Mrotzek, Duck Young Chung, Nishant Ghelani, Tim Hogan, Mercouri G. Kanatzidis

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23 Citations (Scopus)


Several members of the new family A1-xM4-xBi11+xSe21 (A = K, Rb, Cs; M = Sn, Pb) were prepared by direct combination of A2Se, Bi2Se3, Sn (or Pb), and Se at 800°C. The single-crystal structures of K0.54Sn3.54Bi11.46Se21,K 1.46 Pb3.08Bi11.46Se21, Rb0.69Pb3.69Bi11.31Se21,, and Cs0.65Pb3.65Bi11.35Se21 were determined. The compounds A1-xM4-xBi11+x Se21 crystallize in a new structure type with the monoclinic space group C2/m, in which building units of the Bi2Te3 and NaCl structure type join to give rise to a novel kind of three-dimensional anionic framework with alkali-ion-filled tunnels. The building units are assembled from distorted, edge-sharing (Bi,Sn)Se6 octahedra. Bi and Sn/Pb atoms are disordered over the metal sites of the chalcogenide network, while the alkali site is not fully occupied. A grand homologous series Km(M6Se8)m(M5+nSe 9+n) has been identified of which the compounds A1-x M4-xBi11+xSe21 are members. We discuss here the crystal structure, charge-transport properties, and very low thermal conductivity of A1-xM4-xBi11+xSe21.

Original languageEnglish
Pages (from-to)1915-1926
Number of pages12
JournalChemistry - A European Journal
Issue number9
Publication statusPublished - May 4 2001



  • Bismuth
  • Selenium
  • Semiconductors
  • Structure elucidation
  • Thermoelectric materials

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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