Low thermal conductivity CoSb3 materials prepared by rapid synthesis process

Nano-particles and defects have effective influence on reducing the lattice thermal conductivity. In this work, a serious of high concentration Te doping bulk polycrystalline materials Co4Sb11.2Te0.8 has been synthesized successfully at different pressures by the high pressure and high temperature (HPHT) method. All samples were characterized by X-ray diffraction. The Seebeck coefficient alpha, electrical resistivity rho and thermal conductivity kappa were all measured from 373 K to 673 K. It could be observed obviously that, as the synthesis pressure rised, the thermal conductivity of Co4Sb11.2Te0.8 decreased remarkably. The minimum thermal conductivity of 1.36 W m(-1) K-1 was obtained by Co4Sb11.2Te0.8 sample synthesized at 3.7 GPa. The corresponding microstructures were also studied by SEM and HRTEM images.