ChemInform Abstract: Cage‐Forming Compounds in the Ba—Rh—Ge System: From Thermoelectrics to Superconductivity.

Abstract

Superconductivity. -Phase relations in the Ge-rich part of the title system are studied at 700 and 750°C. Two novel phases, τ2-Ba3Rh4Ge16 (I) an τ3-Ba5Rh15Ge35.75 (II) are identified. Their structures are determined by single crystal XRD. (I) crystallizes in the tetragonal space group I4/mm and (II) in the orthorhombic space group Fddd. The phases (I), (II), κ 1 -Ba 8 Rh 1.2 Ge 42 2.0 (III), and τ 1 -BaRhGe 3 (IV) show a change from thermoelectric behavior for (III) to superconducting behavior for (I). The electrical resistivity of (IIII) increases almost linearly from room temperature to 730 K, and the Seebeck coefficient is negative throughout the same temperature range. (IV) has typical metallic electrical resistivity. A superconducting transition occurs for (I) at 6.5 K, whereas (II) shows metallic-like behavior down to 4 K. -(ROGL*, P.; et al.; Inorg. Chem. 52 (2013) 2, 931-943, http://dx.doi.org/10.1021/ic302139r ; Inst. Phys. Chem., Univ. Wien, A-1090 Wien, Austria; Eng.) -W. Pewestorf 14-008