The new compounds CsCu2MTe4 (M = Nb, Ta) have been synthesized at 900°C through the reaction of Cu and Nb or Ta with a Cs2Te3/Te melt as a reactive flux. Single-crystal X-ray diffraction measurements show that both compounds crystallize in the space group Pn21a of the orthorhombic system with four formula units in cells of dimensions a = 8.198(2) Å, b = 5.988(2) Å, c = 20.527(6) Å, V = 1007.7(6) Å3 at 113 K for M = Nb, and a = 8.217(5) Å, b = 5.992(5) Å, c = 20.562(14) Å, V = 1012(1) Å3 at 113 K for M = Ta. The two compounds are isostructural. The structure of CsCu2NbTe4 comprises infinite, two-dimensional layers of Cu-and Nb-centered tetrahedra; Cs+ cations separate the layers. Each Cs+ cation is coordinated by nine Te atoms at the corners of a highly distorted tricapped trigonal prism. Both phases are highly resistive.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry