The new compound Eu0.59Nb5Se8 has been prepared from a combination of the elemental powders at 1275 K. The material crystallizes with four formula units in space group C32h- C2 m of the monoclinic system in a cell (at 113 K) of dimensions a = 17.95(2), b = 3.388(4), c = 19.30(2)Å, β = 107.90(2)°. The structure has been solved and refined from single-crystal X-ray data. The asymmetric unit contains two independent Eu atoms, five independent Nb atoms, and eight independent Se atoms. Each Eu site is approximately 59% occupied; the Eu atoms are in an unusual distorted cube of Se atoms with EuSe interactions ranging from 3.108(6) to 3.454(6) Å. Three of the independent Nb atoms are in trigonal prisms of Se atoms with NbSe interactions ranging from 2.548(6) to 2.617(6) Å while the other two independent Nb atoms are in unusual distorted octahedral environments with NbSe interactions ranging from 2.526(9) to 2.718(7) Å. These latter two Nb atoms show short NbNb interactions of about 2.95 Å. The material exhibits excellent metallic conductivity along the needle (b) direction with σ298 K of 35 × 103 ohm-1 cm-1 and σ12 K ≈ 1.4 × 106ohm-1 cm-1.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry