Cage-Forming Compounds in the Ba-Rh-Ge System: From Thermoelectrics to Superconductivity
- Author(s)
- Matthias Falmbigl, F. Kneidinger, Mingxing Chen, Andrij Grytsiv, Herwig Michor, Esmaeil Royanian, Ernst Bauer, Herta Silvia Effenberger, Raimund Podloucky, Peter Franz Rogl
- Abstract
Phase relations and solidification behavior in the Ge-rich part of the phase diagram have been detd. in two isothermal sections at 700 and 750 °C and in a liquidus projection. A reaction scheme has been derived in the form of a Schulz-Scheil diagram. Phase equil. are characterized by three ternary compds.: t1-BaRhGe3 (BaNiSn3-type) and two novel phases, t2-Ba3Rh4Ge16 and t3-Ba5Rh15Ge36-x, both forming in peritectic reactions. The crystal structures of t2 and t3 have been elucidated from single-crystal X-ray intensity data and were found to crystallize in unique structure types: Ba3Rh4Ge16 is tetragonal (I4/mmm, a = 0.65643(2) nm, c = 2.20367(8) nm, and RF = 0.0273), whereas atoms in Ba5Rh15Ge36-x (x = 0.25) arrange in a large orthorhombic unit cell (Fddd, a = 0.84570(2) nm, b = 1.4725(2) nm, c = 6.644(3) nm, and RF = 0.034). The body-centered-cubic superstructure of binary Ba8Ge43[]3 was obsd. to extend at 800 °C to Ba8Rh0.6Ge43[]2.4, while the clathrate type I phase, ?I-Ba8RhxGe46-x-y[]y, reveals a max. soly. of x = 1.2 Rh atoms in the structure at a vacancy level of y = 2.0. The cubic lattice parameter increases with increasing Rh content. Clathrate I decomps. eutectoidally at 740 °C: ?I
- Organisation(s)
- Department of Physical Chemistry, Department of Theoretical Chemistry, Department of Mineralogy and Crystallography
- External organisation(s)
- Technische Universität Wien
- Journal
- Inorganic Chemistry
- Volume
- 52
- Pages
- 931-943
- No. of pages
- 13
- ISSN
- 0020-1669
- DOI
- https://doi.org/10.1021/ic302139r
- Publication date
- 2013
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 104017 Physical chemistry, 105113 Crystallography
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/d49119b2-0da5-407e-b660-432cf6d1c38c