Syntheses, crystal structures, and physical properties of La 5Cu6O4S7 and La5Cu 6.33O4S7

George H. Chan, Ming Ling Liu, Li Dong Chen, Fu Qiang Huang*, Daniel E. Bugaris, Daniel M. Wells, John R. Ireland, Mark C. Hersam, Richard P. Van Duyne, James A. Ibers

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


Single crystal and bulk powder samples of the quaternary lanthanum copper oxysulfides La5Cu6.33O4S7 and La5Cu6O4S7 have been prepared by means of high-temperature sealed-tube reactions and spark plasma sintering, respectively. In the structure of La5Cu6.33O 4S7, Cu atoms tie together the fluorite-like 2[La5O4S5+] and antifluorite-like 2[Cu6S 65-] layers of La5Cu6O 4S7. The optical band gap, Eg, of 2.0 eV was deduced from both diffuse reflectance spectra on a bulk sample of La 5Cu6O4S7 and for the (010) crystal face of a La5Cu6.33O4S7 single crystal. Transport measurements at 298 K on a bulk sample of La 5Cu6O4S7 indicated p-type metallic electrical conduction with σelectrical = 2.18 S cm -1, whereas measurements on a La5Cu6.33O 4S7 single crystal led to σelectrical = 4.5 10-3 S cm-1 along [100] and to semiconducting behavior. In going from La5Cu6O4S7 to La5Cu6.33O4S7, the disruption of the 2[Cu6S65-] layer and the decrease in the overall Cu2+ (3d9) concentration lead to a significant decrease in the electrical conductivity.

Original languageEnglish (US)
Pages (from-to)4368-4374
Number of pages7
JournalInorganic chemistry
Issue number10
StatePublished - May 19 2008

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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