Year: 2015
Type: article
Abstract: A ternary type-I Si clathrate, K 8 Al x Si 46− x , which is a candidate functional material composed of abundant non-toxic elements, was synthesized and its transport properties were investigated at temperatures ranging from 10 to 320 K. The synthesized compound is confirmed to be the ternary type-I Si clathrate K 8 Al 7 Si 39 with a lattice parameter of a = 10.442 Å using neutron powder diffractometry and inductively coupled plasma optical emission spectrometry. Electrical resistivity and Hall coefficient measurements revealed that K 8 Al 7 Si 39 is a metal with electrons as the dominant carriers at a density of approximately 1 × 10 27 /m 3 . The value of Seebeck coefficient for K 8 Al 7 Si 39 is negative and its absolute value increases with the temperature. The temperature dependence of the thermal conductivity is similar to that for a crystalline solid. The dimensionless figure of merit is approximately 0.01 at 300 K, which is comparable to that for other ternary Si clathrates.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1433479423