Thermoelectric properties of Si2Ti-type Al-Mn-Si alloys

Abstract

By using the first principle band calculations, we identified that Si 2Ti-type Al-Mn-Si C54-phase possesses an electronic structure suitable for the thermoelectric materials. The formation range of the Al-Mn-Si C54-phase was determined by preparing samples at a number of different compositions, and the samples solely consisting of the C54-phase were successfully obtained around Al: Mn : Si = 1 : 1 : 1. The carrier concentration of the Al-Mn-Si C54-phase was controlled by the partial substitution of the constituent elements, and behaviors in electrical properties characteristic to n-type and p-type thermoelectric materials were alternatively observed for the samples of a larger electron concentration and a smaller electron concentration, respectively. The absolute value of the Seebeck coefficient |5| was found to exceed 300 μV/K for both n-type and p-type samples. © 2010 The Japan Institute of Metals.