Substitution effect of Sb on the thermoelectric properties of BaBiO₃

Abstract

BaBi_1-xSb_xO₃ (x = 0.0 - 0.5) ceramics were prepared and the electrical conductivity and Seebeck coefficient were measured at high temperatures to elucidate the substitution effect of Sb on the thermoelectric properties of BaBiO₃. All the ceramics exhibited p-type semiconducting behavior and the electrical conduction for x = 0.0 - 0.4 was attributed to hopping of 6s holes between Bi⁵⁺(6s⁰) and Bi³⁺(6s²). Substitution of Bi with Sb led to the systematic decrease in cell volume, the decrease in electrical conductivity, and the increase in Seebeck coefficient, suggesting that the Sb atoms were doped as Sb⁵⁺ replacing Bi⁵⁺ and reducing 6s holes as carriers. The power factor was maximized for Sb-undoped BaBiO₃ (3*10^-5 Wm^-1K^-2 at 773 K).