| 研究実績の概要 |
This proposal aims to develop high performance, environmental friendly, low cost and stable half-Heusler thermoelectric materials based on the introduction of multiscale microstructure in order to recycle waste heat energy from any high temperature source. In order to achieve the goal, much better improvement on fundamental understanding of the multiscale microstructure, which includes microstructure with different length scales, i.e. (a) the atomic point defects, (b) the nanoscopic Heusler nanoprecipitates, (c) the microscopic half-Heusler-half-Heusler domains, and (d) the mesoscopic grain size, of the alloys. At this stage, a series of (Tix,Zr1-x)NiySn half-heusler alloys have been fabricated and we have direct experimental evidence showing that (b) and (c) can be controlled by composition tunning and cyclic heat treatment processes. Most importantly, by increasing surface area density of microstructure(b) and (c), as well as changing their interfacial structure to relatively more diffuse, thermal conducvity of the alloys can be reduced greatly, just like what have expected.
|
| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
As mentioned earlier, we intend to improve the fundamental understanding on formation of multiscale microstructure (i.e. atomic defects, nanoprecipitates, microscopic half-Heusler-half-Heusler domains and the mesoscopic grain size) utilise it to improve thermoelectric properties of half-Heusler alloys. So far, half of the multi-length scale microstructure have been investigated, and direct experimental evidences have been obtained showing how they can be contolled for improving thermoelectric properties of the alloys.
|
| 今後の研究の推進方策 |
In this fiscal year, we continue to investigate and obtain direct experimental evidence showing how the atomic defects and grain size affect thermoelectric propeties of the alloys. Next, alloys containing the all-length-scale microstrutcure will be fabricated and evaluated their effect towards thermoelectric properties of half-Heusler.
|
