Alkali-metal-filled CoSb_3 skutterudites as thermoelectric materials: Theoretical study

摘要

The crystal structures, filling fraction limits (FFLs), electronic structures, and electrical transport properties for alkali-metal-filled CoSb_3 skutterudites are studied using density functional band-structure calculations. The calculated FFLs in CoSb_3 are more than 60% for Na and K, 25% for Rb, and zero for Li and Cs, at 1000 K. The reasons for these unusual FFLs of alkali atoms are discussed. Based on the calculated electronic structures, the electrical transport properties of CoSb_3 are likely to be retained upon Na and K fillings, which was also confirmed by our calculated electrical transport properties of these materials. Furthermore, excellent thermoelectric properties are expected for Na-filled CoSb_3 skutterudites.