AbstractWe have prepared a variety of filled skutterudites through non-equilibrium synthesis by converting melt-spun ribbons into single phase polycrystalline bulk under pressure. In general, better thermoelectric properties are found in these samples. In this work, we performed microstructure characterization of non-equilibrium synthesized p-type filled skutterudite CeFe4Sb12 by X-ray diffraction, scanning electron microscopy and transmission electron microscopy in order to understand the structural origin of the improved thermoelectric properties. It is found that the non-equilibrium synthesized samples have smaller grain size and cleaner grain boundaries when compared to the samples prepared by the conventional solid-state reaction plus long term annealing. While smaller grain size can help reduce the lattice thermal conductivity, cleaner grain boundaries ensure higher carrier mobility and subsequently, higher electrical conductivity at the application temperatures.
Simulation of the charge transport across grain boundaries in p-type SrTiO3 ceramics under dc load: Debye relaxation and dc bias dependence of long-term conductivity
