Huge thermopower of porous Y2O3

Abstract

Porous Y2O3 ceramic was found to show huge thermopower values up to −50 mV/K at 900–1000 K in vacuum, but not in air. Such huge thermopowers may be generated by the electron gas emitted from the internal surfaces of the pores and are associated with some unknown effects. The nondimensional thermoelectric figure of merit, ZT, of this porous ceramic was as large as ∼0.95 at ∼950 K, and hence, it can be used as a thermoelectric material.