Improved process for synthesizing n-type and p-type β-FeSi2 thermoelectric material from attritor milled powder

Abstract Semiconducting iron disilicide, β-FeSi2, has its application in thermoelectric generators using p-type and n-type semiconducting β-FeSi2. It is useful for energy conversion (waste heat energy to electrical energy) in the temperature range between 200 and 900 °C. The peritectoid and eutectoid reaction responsible in the formation of β-FeSi2 phase are very sluggish. This research work focuses on shortening of sintering period and thus conserving energy required for complete transformation of various phases to β-FeSi2. Total time required for the synthesis along with the sintering cycle is relatively less (about 20 h) than the other processes (other process durations varying from 37 h to 504 h) studied earlier. An innovative sintering cycle was developed to achieve nearly complete β-FeSi2 phase formation. p-type and n-type semiconducting β-FeSi2 were characterized for thermoelectric properties.