Rapid preparation of high-performance S0.4Co4Sb11.2Te0.8 skutterudites with a highly porous structure

In this study, S0.4Co4Sb11.2Te0.8 skutterudites with a highly porous structure inside grains are prepared by a onestep hot-pressing (OS-HP) method. The effect of the pressure relief treatment at the heating stage on the micromorphology and thermoelectric properties of materials is investigated. When the temperature corresponding to the pressure relief treatment is less than 723 K, the grain size dramatically increases from -1 to -50 ?m, and a large number of pores are distributed inside these large grains. Compared with those samples prepared by the conventional method, the thermal conductivity of samples prepared by the pressure relief treatment is significantly reduced due to the high porosity. The ZT values of samples prepared by the pressure relief treatment are greater than 1.6 at 825 K. This newly developed OS-HP method can be employed for the rapid fabrication of highly porous structured skutterudites with low-melting-point compositions as well as of other material systems.

Automated summary

The study shows that relieving pressure during heating can significantly increase the grain size and internal porosity of skutterudites, leading to reduced thermal conductivity and higher ZT values. This newly developed OS-HP method allows for rapid fabrication of highly porous structured skutterudites with low-melting-point compositions.