Thermoelectric conversion material comprising a full-Heusler alloy and method for manufacturing the same by alloying and successively heating a raw material

摘要

The present invention provides a metal-based thermoelectric conversion material having a high figure-of-merit ZT, the thermoelectric conversion material being a p-type or n-type full-Heusler alloy, having a composition of an Fe2TiA type (wherein A is Si and/or Sn), and including crystal grains having an average grain diameter of 30-500 nm. In particular, in the case where the composition of an Fe2TiA type is represented by the empirical formula Fe2+σTi1+yA1+z, the values of σ, y, and z in an Fe—Ti-A ternary alloy phase diagram lie within the range α surrounded by the points (50, 37, 13), (45, 30, 25), (39.5, 25, 35.5), (50, 14, 36), (54, 21, 25), and (55.5, 25, 19.5) in terms of (Fe, Ti, A) in at %.