  Oxide thermoelectrics are exciting due to their chemical and thermal
stability at high temperatures. However, the efficacy of these materials are
limited by poor figure of merit (zT). In this study, the role of Sr and Mn
co-substitution on the thermoelectric properties of NdCoO3
(Nd_{1-x}Sr_xCo_{1-y}Mn_yO_3; 0.00 \leq x \leq 0.10; 0.00 \leq y \leq 0.10) is
investigated. The Seebeck coefficient decreases with single Sr substitution at
Nd site; however, the Sr and Mn co-substitution enhances the Seebeck
coefficient compared to single Sr substitution and is attributed to the
localization effect. Sr substitution at La site creates hole in the system and
results in enhanced electrical conductivity ({\sigma}); however, {\sigma}
reduces with Mn substitution at Co site in NdCoO_3. A reduced thermal
conductivity for the co-substituted samples is observed and attributed to
decrease in phonon thermal conductivity. Simultaneous optimization of TE
parameters results in improved zT \sim 0.038 for
Nd_{0.95}Sr_{0.05}Co_{0.95}Mn_{0.05}O_3 at 540 K.
