Effect of manganese doping on the thermoelectric properties of Zintl phase EuCd2Sb2

Polycrystalline samples of Zintl phase EuCd2–xMnxSb2 (0.0≤x≤0.6) with the CaAl2Si2-type crystal structure (space group) were synthesized via a solid-state reaction followed by suitable cooling, annealing and spark plasma sintering (SPS) processes. In samples with x=0.0, 0.1, 0.2, 0.4 and 0.6, the electrical conductivity, Seebeck coefficient, and thermal conductivity were performed as a function of temperature from 300 to 650 K. It was found that chemical substitution of Mn failed to optimize the thermoelectric properties of p-type conductive EuCd2Sb2. It was because that the Mn substitution induced the minority carriers (electrons), resulting in decreasing the electrical conductivity drastically despite the fact that it enlarged the Seebeck coefficient and reduced the thermal conductivity synchronously.

Graphical AbstractThe Mn substitution on the Cd site fails to optimize the Zintl phase EuCd2Sb2, which is because that the Mn substitution induces the minority carriers (electrons), resulting in decreasing the electrical conductivity drastically despite the fact that it enlarges the Seebeck coefficient and reduces the thermal conductivity synchronouslyFigure optionsDownload as PowerPoint slide