Thermoelectric properties of cobalt rhodium oxides: [Bi2Ba2O4]p(Co,Rh)O2

We successfully synthesized polycrystalline samples of [Bi₂ Ba₂O₄]_p(Co,Rh)O₂ (BBCRO) with Co and Rh mixed (Co,Rh)O₂ layers by solid-state reaction. The X-ray diffraction pattern and the electron diffraction patterns indicate that the structure of this compound is similar to the structure of [Bi₂Ba₂O₄]_pRhO ₂ (BBCO) and [Bi₂Ba₂O₄]_pCoO₂ (BBRO). The thermopower and the resistivity of BBCRO are 102 muV/K and 62 mOmegacm at room temperature, respectively. The temperature dependence of thermopower is similar to that of BBCO and BBRO. The resistivity, however, shows semiconducting behavior, which is different from that of BBCO and BBRO