Thermoelectric properties of Mg{sub}2Si{sub}(1-x)C{sub}x crystals grown by the vertical Bridgman method

摘要

Multicrystalline Mg{sub}2Si crystals were grown using a Brigdman method combined with a die-casting growth technique. Although molten and/or vapor-phase Mg at elevated growth temperatures exhibit high chemical reactivity with the surrounding crucible materials, the use of an alumina crucible with a BN coating allowed single phase crystal growth and Mg{sub}2Si of good crystalline quality. Incorporation of carbon into the Mg{sub}2Si was observed to form Mg{sub}2Si{sub}(1-x)C{sub}x. For x=0.01 and 0.03, a lower thermal conductivity and higher figure of merit than those of Mg{sub}2Si were observed in the temperature range from room temperature to 773 K. The maximum figure of merit was 0.62 at 773 K for a Mg{sub}2Si{sub}0.99C{sub}0.01 sample.