Composites containing Yb-filled CoSb3 and well-distributed Yb2O3 particles are synthesized by in situ reaction method. The structural, chemical, and transport properties of the composites are studied. Some Yb2O3 particles with microsize locate at the grain boundaries of matrix and others distribute within Yb yCo4Sb12 grains as nanoscale inclusions. The combination of the "rattling" of Yb ions inside the voids of CoSb 3 and the phonon scattering of the oxide defects results in a remarkable reduction in the lattice thermal conductivity. The thermoelectric performance of the composites is significantly improved, and the maximum figures of merit reach 1.3 for the Yb0.25Co4Sb 12/Yb2O3 and 1.2 for the Yb 0.21Co4Sb12/Yb2O3 composites at 850 K.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)