| Project/Area Number |
26288105
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Partial Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Inorganic industrial materials
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
Yamada Takahiro 東北大学, 多元物質科学研究所, 准教授 (10358260)
|
|---|
| Co-Investigator(Renkei-kenkyūsha) |
YAMANE Hisanori 東北大学, 多元物質科学研究所, 教授 (20191364)
|
|---|
| Project Period (FY) |
2014-04-01 – 2017-03-31
|
| Project Status |
Completed (Fiscal Year 2016)
|
| Budget Amount *help |
¥17,420,000 (Direct Cost: ¥13,400,000、Indirect Cost: ¥4,020,000)
Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2015: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2014: ¥15,210,000 (Direct Cost: ¥11,700,000、Indirect Cost: ¥3,510,000)
|
|---|
| Keywords | 熱電材料 / ジントル化合物 / トンネル構造 / 結晶構造 / 金属間化合物 / 結晶構造解析 |
|---|
| Outline of Final Research Achievements |
Ternary Zintl phases in the Na-Tr-Sn system (Tr=Al, Ga, In, Zn) were synthesized, and their thermoelectric properties were characterized. It is revealed that the sintered compacts or ingots of Na2+xTr2+xSn4-x (Tr = Al, Ga, In) and Na2ZnSn5 dimorphs, which have similar crystal structures, showed relatively high thermoelectric figures of merit with low thermal conductivities close to or less than 1 W m-1 K-1. A sintered compact of Na2+xGa2+xSn4-x, (x = 0.19) with a relative density of 73% showed highest dimensionless figure of merit, ZT, of 0.98 at 295 K, which is comparable to the performance of the Bi2Te3-based practical materials. In the crystal structures of the ternary Zintl phases in this study, helical tunnels are formed in a framework structure composed of Tr and Sn atoms, and a Na site with an occupancy of around 1/3 to 1 is located in the tunnels. The low thermal conductivities were probably due to disorder arrangement and large thermal vibration of Na atoms in the tunnels.
|
