Abstract
A molten Al flux method was used to grow single crystals of the type I clathrate compound Ba8Al14Si31. Single-crystal neutron diffraction data for Ba8Al14Si31 were collected at room temperature using the SCD instrument at the Intense Pulsed Neutron Source, Argonne National Laboratory. Single-crystal neutron diffraction of Ba8Al14Si31 confirms that the Al partially occupies all of the framework sites (R1 = 0.0435, wR2 = 0.0687). Stoichiometry was determined by electron microprobe analysis, density measurements, and neutron diffraction analysis. Solid-state 27Al NMR provides additional evidence for site preferences within the framework. This phase is best described as a framework-deficient solid solution Ba8Al 14Si31, with the general formula, Ba8Al xSi42-3/4x[]4-1/4x ([] indicates lattice defects). DSC measurements and powder X-ray diffraction data indicate that this is a congruently melting phase at 1416 K. Temperature-dependent resistivity reveals metallic behavior. The negative Seebeck coefficient indicates transport processes dominated by electrons as carriers.
Original language | English (US) |
---|---|
Pages (from-to) | 9381-9386 |
Number of pages | 6 |
Journal | Inorganic Chemistry |
Volume | 45 |
Issue number | 23 |
DOIs | |
State | Published - Nov 13 2006 |
ASJC Scopus subject areas
- Inorganic Chemistry