Thermoelectric properties of Nowotny phase, higher manganese silicides synthesized by mechanical alloying process

Higher manganese slicides (HMS), MnSi1.73, were synthesized by the mechanial alloying of stoichiometric elemental powder compositions, and the as-milled powders were consolidated by vacuum hot pressing. Phase transformation and microstructural evolution during mechanical alloying and hot consolidation were investigated using XRD and SEM, respectively. Thermoelectric properties as a function of temperature were evaluated in terms of Seebeek coefficient, electrical resistivity, thermal conductivity and the figure of merit. Transport properties were also evaluated and discussed with analogue studies. Mechanically alloyed HMS showed the figure of merit value of 0.5 at 823 K, and appeared to have a great potential as a thermoelectric material.