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Thermoelectric materials are receiving increasing interest as a means of energy production, particularly because of their ability to capture the waste heat lost by industrial processes and automobiles. 1) Thermoelectric performance is characterized by the dimensionless figure of merit, ZT, which is defined as ZT=· S2T/¬, where· is electrical conductivity, S is the Seebeck coefficient,¬ is thermal conductivity and T is temperature. Achieving a high ZT by optimizing these parameters is the goal of thermoelectric research; however, the interrelation of these parameters proves to be a challenge to obtaining a high ZT. Current practical high-temperature thermoelectric materials such as PbTe and SiGe typically have ZT= 1 or better, but a drawback of these materials is their high cost, use of toxic and rare elements and instability in air or at high temperatures. 1) Oxide thermoelectrics, which are low cost, use abundant and environmentally benign elements and have stability in air and at high temperatures, offer a potential solution to the challenges faced by conventional thermoelectric materials. Moderate ZT values have been achieved in a number of oxides, such as single crystal p-type NaxCo2O4 (ZT= 1.0 at 800 K), 2) n-type Nb-doped SrTiO3 (ZT= 0.35 at 1000K) 3) and n-type Al-doped ZnO (ZT= 0.3 at 1273 K and ZT= 0.44 at 1000 K). 4), 5) By doping or changing stoichiometry it has proven possible to increase the

ZT of select oxides to near practical efficiency. Nevertheless, challenges such as the question of stability of NaxCo2O4 at high temperature due to the volatility of Na as well as the lack of an n-type oxide thermoelectric with a ZT near 1 remain and …