Published online by Cambridge University Press: 31 January 2011
A new process, based on melt processing has been investigated with oxide thermoelectrics to achieve long-range grain alignment for low resistivity as well as to embed secondary phase precipitates and associated crystal defects for low thermal conductivity. Melt-processing of Bi2Sr2Co2Ox and CaMnO3 has been studied. A high degree of (00l) grain alignment has been achieved by melt processing. Good values of Seebeck coefficient of nearly -250 μV/K were measured in the melt-processed CaMnO3. Secondary phases of Ca4Mn3O10 and CaMn2O4 are found to be trapped between the aligned grains which led to high electrical resistivity values and limited the figure of merit in our initial samples.