Influence of sintering temperature on the microstructure and thermoelectric properties of polycrystalline Fe1.9925P0.0075O3.

The solution combustion process is used to synthesize Fe1.9925P0.0075O3 nano-powders. The sintered Fe1.9925P0.0075O3 bodies are alpha-Fe2O3-based single phase with the rhombohedral structure. The electrical conductivity increases with an increase in sintering temperature because of an increase in grain size and density. The absolute value of the Seebeck coefficient escalates with an increase in sintering temperature up to 1000 degrees C, and then decreases with a further rise in its sintering temperature. The Fe1.9925P0.0075O3 sintered at 1000 degrees C shows the highest power factor, i.e., 1.39 x 10(-5) W m(-1) K(-2) at 700 degrees C.