The type VIII clathrate Ba 8Ga 16Sn 30 has a relatively high figure of merit (ZT) from 200°C to 400°C. Our previous calculations showed that the optimum carrier concentration for high ZT is on the order of 10 20/cm 3 for both p- and n-type samples. The ZT value exceeds unity for the n-type material. However, actual carrier concentrations for synthesized samples were on the order of 10 19/cm 3. With the aim of increasing the carrier concentration, we have synthesized single crystals of Sb-doped Ba 8Ga 16Sn 30. Contrary to our expectation, the Ga content in the crystal increased with the increase in Sb content. In both p- and n-type samples, the carrier concentration was increased, and the power factor for the p-type samples was improved to 1.4 × 10 -2 W/mK 2. These results are discussed in relation to the change in the band structure.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry