Fabrication and thermoelectric characteristics of [(Bi,Pb)2Ba2O4±w]0.5CoO2 bulks with highly aligned grain structure

Here, we report fabrication and thermoelectric characteristics of polycrystalline bulks with aligned grains of the misfit-layered cobalt oxides, [(Bi1-xPbx)(2)Ba2O4 +/- w](0.5)CoO2. High-quality precursor powder was prepared with a spray-drying technique. The precursor was then sintered under a uniaxial pressure to yield dense bulk samples consisting of highly aligned grains. The electrical conductivity of such samples was four times higher than that of conventionally sintered bulks. Accordingly, the thermoelectric characteristics of the grain-aligned specimens were enhanced. (C) 2008 American Institute of Physics.