1. Influence of in-situ formed MoSi2 inclusions on the thermoelectrical properties of N-type silicon-germanium alloy
- Author
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Jean Leforestier, Mathieu Soulier, Jean-Claude Tedenac, Katia Favier, Mathieu Boidot, Didier Ravot, Guillaume Bernard-Granger, Christelle Navone, Julia Simon, Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), and Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,Polymers and Plastics ,Metallurgy ,Composite number ,Alloy ,Doping ,Metals and Alloys ,chemistry.chemical_element ,Sintering ,Spark plasma sintering ,Germanium ,engineering.material ,Thermoelectric materials ,Electronic, Optical and Magnetic Materials ,chemistry ,Molybdenum ,Ceramics and Composites ,engineering ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Composite material - Abstract
International audience; An N-type Si92Ge08 (7000 at. ppm P doping) powder (matrix) prepared by mechanical alloying was homogeneously mixed with 1.3 vol.% nanosized molybdenum. The "composite" and matrix powders were sintered by spark plasma sintering, using optimized parameters. The as-sintered "composite" material exhibits a dimensionless thermoelectrical figure of merit (ZT) of ∼1.0 at 700 °C. For the same temperature, the ZT value is only 0.7 for the as-sintered matrix alone. In the composite material, transmission electron microscopy observations enable the detection of nanosized (average diameter of ∼30 nm) MoSi2 inclusions that formed in situ during sintering via the reaction between the native silicon-germanium matrix and the added molybdenum particles. The presence of such nanosized inclusions reduces significantly the lattice contribution to the thermal conductivity of the sintered "composite" material, explaining the strong increase of the ZT parameter in comparison to the sintered matrix alone.
- Published
- 2014