Roles of Binary Bi2o3-2cuo Additives in Regulating the Thermoelectric Properties of (Ca0.87ag0.1dy0.03)3co4o9 Composites Ceramics

Exploring the impact of secondary phase that modulates charge carrier transporting is crucial in order to achieve high thermoelectric properties of Ca 3 Co 4 O 9 -based ceramics. Binary Bi 2 O 3 -2CuO addition was introduced into the matrix. The obvious plate-like grains were observed and the components were verified. The work function of 3.71eV was acquired to resolve the potential barrier. By the sintering samples in increasing Bi 2 O 3 -2CuO content, the gradually reduction in electrical resistivity and the enhancement in Seebeck coefficient were attributed to liquid-phase sintering. The importing of CuO phase promoted the formation of liquid phase. As a result, a maximum ZT value of 0.23 was obtained at 1073 K. It is an effective way to meet the performance deterioration and confirm an important role on the charge carrier transporting and phonons scattering of oxides thermoelectric ceramics.