The new Zintl phase Yb5In2Sb6 was obtained from a direct element combination reaction in a sealed graphite tube at 700°C and its structure was determined. It crystallizes in the orthorhombic space group Pbam (No. 55), in the Ba5Al2Bi6 structure type, with a unit cell of a=7.3992(5) Å, b=23.001(6) Å, c=4.5139(4) Å, and Z=2. Yb5In2Sb6 has a one-dimensional structure with infinite anionic double chains (In2Sb6)10- separated by Yb2+ ions. Each single chain is made of corner-sharing InSb4 tetrahedra. Two such chains are bridged by Sb2 groups to form double chains 1/∞ [In2Sb6/10-]. The compound satisfies the classical Zintl concept and is a narrow gap semiconductor. Band structure calculations suggest an direct band gap. Polycrystalline ingots of Yb5In2Sb6 showed electrical conductivity of 100 S/cm and a Seebeck coefficient of ~ +30 μ V/K at room temperature. The thermal conductivity of Yb5In2Sb6 is about 1.7 W/mK in the temperature range of 150-300 K. (C) 2000 Academic Press.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry