Thermopower enhancement in the layered cobaltate oxide perovskite at high Na doping was investigated. The conducting layered cobaltate Na xCoO2 was found to exhibit several interesting electronic phases as the Na content x is varied, including water-induced superconductivity and an insulating state. Measurements showed that, in the as-grown composition, NaxCoO2 has moderately large thermopower and conductivity. It was observed that, in the poorly explored high-doping region x>0.75, thermopower undergoes an even steeper enhancement. It was found that the 40-fold enhancement of the figure of merit realized at 80 K greatly improves the prospects for thermo-electric applications.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering