Silicon-rich higher manganese silicides for thermoelectric applications

Thermoelectrics are widely explored as a renewable and environmentally friendly method for converting waste heat to electrical power. Higher manganese silicides (HMS) have been identified as promising, nontoxic, inexpensive, p-type materials for thermoelectric applications. To mass-produce practical thermoelectric converters, an inexpensive, effective, and simple production method should be applied for these materials. In the frame of the current research, HMS have been synthesized using furnace melting followed by powdering and spark plasma sintering. Highly dense samples were obtained and measured for their thermoelectric properties. The samples were also characterized using x-ray diffraction, scanning electron microscopy, and Hall-effect measurements. Homogeneous samples were obtained with small inclusions of Si, reaching a figure of merit of about 0.6 at 450°C.