Low thermal conductivity of endogenous manganese silicide/Si composites for thermoelectricity

Suresh Perumal (1) , Stéphane Gorsse (2) , Ujwala Ail (1) , Mythili Prakasam (2) , Solange Vivès (2) , Rodolphe Decourt (2) , Arun M. Umarji (1)

1 Materials Research Centre
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Higher manganese silicide (HMS) based alloys with eutectic composition (Si-33.3 at% Mn) were prepared by arc-melting, melt-spinning and ball milling in order to evaluate the effect of microstructure on the thermal conductivity. Powder X-ray diffraction, SEM, EPMA and TEM analysis confirmed the presence of Si as a secondary phase distributed in the HMS matrix phase. Thermal properties of the samples were studied in the temperature range of 300–800 K. The microstructure refinement resulting from ball milling leads to a decrease of the thermal conductivity from 4.4 W/mK to 1.9 W/mK, whereas melt-spinning is inefficient to this respect. The results show an opportunity to produce bulk higher manganese silicide alloys with reduced thermal conductivity in order to enhance its thermoelectric performance.

Mots clés: Higher manganese silicides; Spark plasma sintering; Hot uni-axial pressing; Thermoelectric properties; Mechanical alloying

Domaines: Matériaux

Suresh Perumal, Stéphane Gorsse, Ujwala Ail, Mythili Prakasam, Solange Vivès, et al.. Low thermal conductivity of endogenous manganese silicide/Si composites for thermoelectricity. Materials Letters, 2015, 155, pp.41-43. ⟨10.1016/j.matlet.2015.04.098⟩. ⟨hal-01153592⟩