ABSTRACT
Signicant improvements in thermoelectric efciency have been achieved in the past decade owing to both innovations in controlling thermal and electronic transport properties and to the discovery of a large number of entirely new thermoelectric materials. Zintl phases represent an important and incredibly diverse new class of thermoelectrics [1-3], with promising novel structure types and compounds being reported on a frequent basis [4,5]. Zintl phases are a subset of intermetallic compounds that are characterized by covalently bonded anionic “substructures,” surrounded by highly electropositive cations [6,7]. Their unique combination of covalent and ionic bonding, together with a high degree of structural complexity, leads to excellent thermoelectric properties, as evidenced by initial reports of ZT ~1 in compounds such as YbZn2Sb2, Zn4Sb3, and Yb14MnSb11 [8-10].
