Abstract

The rare earth praseodymium doped Ca_3−xPr_xCo₄O₉ (x = 0.05, 0.1, 0.2 and 0.3) thermoelectric bulk materials are fabricated by combining sol–gel with spark plasma sintering method. The bulk specimens are characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effects of Pr doping on thermoelectric transport properties have been investigated. The results show that all specimens are single-phased; the grain orientated bulks present deteriorated texture. The polaron carrier conduction mechanism is not changed and the electrical conduction is tuned as a result of carrier concentration modification, thereby an enhanced Seebeck coefficient. The total thermal conductivity is suppressed mainly due to the phonon thermal conduction confinement. The thermoelectric performance of the bulk material is optimized at x = 0.2.

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