Thermoelectric properties of Co-doped BiFeO3 and Bi24CoO37–BiFeO3 compound systems

We investigated the thermoelectric properties of doped multiferroic material: Co-doped BiFeO3 (BFO) and related materials: Bi24CoO37 and Bi24CoO37-BFO composite systems. Because of their insulating nature, the BFO-based samples showed high Seebeck coefficients compared with other oxides being explored as candidates for new thermoelectric materials such as NaCo2O4, and La0.9Sr0.99Ca0.11CoO4. On the other hand, the Bi24CoO37 sample showed high conductivity. The Bi24CoO37 (20%)-BFO composite sample showed a high power factor, because of its high conductivity and high Seebeck coefficient. These results indicated that the BFO matrix plays an important role in maintaining a high Seebeck coefficient, and that Bi24CoO37 works as a conductive pass on this system. (C) 2013 The Ceramic Society of Japan. All rights reserved.