Perovskite type Ca 12x Dy x Mn 12x Nb x O 3 ceramics (x#0?10) are synthesised by solid state reaction. Microstructures are characterised, and the thermoelectric properties are evaluated between 300 and 1100 K. The samples obtained in this work have high relative densities. The electrical resistivity shows a typical metallic conductivity behaviour and decreases with substitution, the variation of which is not significant in whole measured temperature range. The Seebeck coefficients are negative, indicating n type conduction, and the largest value is obtained, 2174 mV K 21 , at x50?02. The highest power factor is 258 mW (K 2 m) 21 for the x50?02 sample. A maximum ZT value reaches 0?08 for electron doped Ca 0?98 Dy 0?02 Mn 0?98 Nb 0?02 O 3 at 973 K, which is about twice as high as that of undoped CaMnO 3 .

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