ICT2014 Abstracts

Higher Manganese Silicides are believed to form different compounds including Mn₄Si₇, Mn₁₁Si₁₉, Mn₁₅Si₂₆, and Mn₂₇Si₄₇, with the Nowotny chimney-ladder structures [1, 2]. These structures can be described as built up by the Mn sublattices forming the chimneys in which the Si sublattices arrange as the ladders.  The various compounds possess similar and parameters, and different  one, depending on the ratio  of the two sublattices. These compounds are promising candidates as p-type legs for thermoelectric modules. They are composed of two of the most abundant elements on the earth, environmentally friendly, and have high mechanical, thermal, and chemical resistance.

Until now, the thermoelectric performance of Higher Manganese Silicides (HMS) is only at a moderate level, mainly due to their high thermal conductivity compared to the conventional materials such as Bi₂Te₃ and PbTe. In this study, we report a reduction of lattice thermal conductivity by introducing nanoinclusions. We demonstrate that the distribution of these inclusions inside the matrix plays an important role in their effects on the materials. The preliminary results show a decrease of up to 30% of the thermal diffusivity for the HMS with 1 wt.-% of nanoinclusions. The detailed thermoelectric properties and microstructure will be presented during the poster session.

1. J. M. Higgins et al., J. Am. Chem. Soc. 130, 16086 (2008)
2. Y. Miyazaki et al., Phys. Rev. B 78, 214104 (2008)