1. Phase Content Influence on Thermoelectric Properties of Manganese Silicide-Based Materials for Middle-High Temperatures
- Author
-
A. Famengo, S. Battiston, M. Fabrizio, Stefano Boldrini, S. Fiameni, Muhammet S. Toprak, Mohsin Saleemi, Filippo Agresti, and Simona Barison
- Subjects
Thermogravimetric analysis ,Materials science ,Metallurgy ,Analytical chemistry ,Spark plasma sintering ,SPS ,Condensed Matter Physics ,thermoelectricity ,Electronic, Optical and Magnetic Materials ,Tetragonal crystal system ,Differential scanning calorimetry ,Thermal conductivity ,Manganese silicide ,Seebeck coefficient ,Thermoelectric effect ,Materials Chemistry ,Thermal stability ,Electrical and Electronic Engineering - Abstract
The higher manganese silicides (HMS), represented by MnSix (x = 1.71 to 1.75), are promising p-type leg candidates for thermoelectric energy harvesting systems in the middle-high temperature range. They are very attractive as they could replace lead-based compounds due to their nontoxicity, low-cost starting materials, and high thermal and chemical stability. Dense pellets were obtained through direct reaction between Mn and Si powders during the spark plasma sintering process. The tetragonal HMS and cubic MnSi phase amounts and the functional properties of the material such as the Seebeck coefficient and electrical and thermal conductivity were evaluated as a function of the SPS processing conditions. The morphology, composition, and crystal structure of the samples were characterized by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray diffraction analyses, respectively. Differential scanning calorimetry and thermogravimetric analysis were performed to evaluate the thermal stability of the final sintered material. A ZT value of 0.34 was obtained at 600°C for the sample sintered at 900°C and 90 MPa with 5 min holding time.
- Published
- 2013