Four New Actinide Chalcogenides Ba2Cu4USe6, Ba2Cu2ThSe5, Ba2Cu2USe5, and Sr2Cu2US5: Crystal Structures and Physical Properties

Adel Mesbah, Jai Prakash, Jessica C. Beard, Sébastien Lebègue, Christos D. Malliakas, James A. Ibers*

*Corresponding author for this work

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

Four new actinide chalcogenides - namely, Ba2Cu4USe6, Ba2Cu2ThSe5, Ba2Cu2USe5, and Sr2Cu2US5 - were synthesized via solid-state methods at 1173 K. Single-crystal X-ray diffraction studies show that Ba2Cu4USe6 crystallizes in a new structure type in space group C2h5-P21/c of the monoclinic system, whereas the three other compounds are isostructural and adopt the Ba2Cu2US5 structure type in space group C2h3-C2/m, also of the monoclinic system. These Ak/Cu/An/Q structures (Ak = alkaline-earth metal; An = actinide; Q = chalcogen) have no short Q-Q interactions and, hence, are charge-balanced with Ak2+, Cu1+, An4+, and Q2-. Crystal structures of all these compounds are two-dimensional and feature layers that are separated by Ba2+ cations. The compositions of these layers differ. In the structure of Ba2Cu4USe6, the 2[Cu4USe64-] layers comprising USe6 octahedra and CuSe4 tetrahedra stack perpendicular to the a-axis. These 2[Cu4USe64-] layers show short Cu-Cu interactions. In the three isostructural Ak2Cu2AnQ5 compounds, AnQ6 octahedra and CuQ4 tetrahedra are connected along the c-axis in the sequence "...oct tet tet oct tet tet..." to form the 2[Cu2AnQ54-] layers. Resistivity, optical, and DFT calculations show semiconducting behavior for these compounds.

Original languageEnglish (US)
Pages (from-to)9138-9145
Number of pages8
JournalInorganic chemistry
Volume54
Issue number18
DOIs
StatePublished - Sep 11 2015

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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