The Higher manganese silicides (HMS), represented by MnSix (x=1.71-1.75), are promising p-type leg candidates for thermoelectric harvesting energy system in the middle-high temperature range. They are very attractive as they could replace lead based compounds due to their non toxicity, low cost of starting materials, high thermal and chemical stability. Nanostructured dense pellets were obtained through the direct reaction between Mn and Si powders during the spark plasma sintering process. The tetragonal HMS and the cubic MnSi phase amounts were related to the SPS process conditions and the functional properties of the material such as Seebeck coefficient, electrical and thermal conductivity (the latter was carried out by means the Laser Flash analysis). The morphology, the composition and the crystallographic structure of the samples were characterized by FE-SEM, EDS and XRD analyses, respectively. Differential Scanning Calorimetry was performed in order to understand the behavior of Mn and Si powder during the reaction and the stability of the final material. The influence of the nanostructure on the material features was also discussed.
Phase content influence on thermoelectric properties of nanostructured manganese silicide based materials for middle-high temperature
S Battiston;A Famengo;S Boldrini;S Fiameni;F Agresti;M Fabrizio;S Barison
2012
Abstract
The Higher manganese silicides (HMS), represented by MnSix (x=1.71-1.75), are promising p-type leg candidates for thermoelectric harvesting energy system in the middle-high temperature range. They are very attractive as they could replace lead based compounds due to their non toxicity, low cost of starting materials, high thermal and chemical stability. Nanostructured dense pellets were obtained through the direct reaction between Mn and Si powders during the spark plasma sintering process. The tetragonal HMS and the cubic MnSi phase amounts were related to the SPS process conditions and the functional properties of the material such as Seebeck coefficient, electrical and thermal conductivity (the latter was carried out by means the Laser Flash analysis). The morphology, the composition and the crystallographic structure of the samples were characterized by FE-SEM, EDS and XRD analyses, respectively. Differential Scanning Calorimetry was performed in order to understand the behavior of Mn and Si powder during the reaction and the stability of the final material. The influence of the nanostructure on the material features was also discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
