The thermoelectric properties of two thermoelectric materials (Ca3Co4O9+delta and Ca3−xPrxCo3.95Ga0.05O9+delta) were investigated in this paper. The power factor of one of the samples was improved by 52% relative to the others. The second material tested had a 50% improvement in the figure of merit over the first material. The study concluded that partial substition of the Pr3+ ions can improve the thermoelectric properties of these ...