| Summary: | 碩士 === 國立中央大學 === 材料科學與工程研究所 === 105 === Higher manganese silicide (HMS) is considered to be a promising p-type thermoelectric material for use in intermediate-temperature power generation. It is well known that HMS exist as several incommensurable phases such as Mn4Si7, Mn11Si19, Mn15Si26, Mn27Si47, and all of these compounds are Nowotny chimney phases exhibiting tetragonal crystal structure.
Thermoelectric performance is improved through compositional optimization by doping or substitution. In this work, we prepared polycrytstalline HMS with Sn additions by arc melting and subsequent spark plasma sintering (SPS). The phases, composition, and microstructures of the Sn-doped polycrystalline HMS bulk were investigated. In this study, we select doped-Sn ratio of 0.1at%, 0.5 at%, 1 at%, and 1.5at%. After SPS, we measured the thermoelectric properties of sintered bulk sample from 323K to 773K. We found that the thermal conductivity was significantly improved when the Sn was 0.1at%. The HMS with Sn has the best the ZT is 0.1at%.
|
|---|
