Effects of single and double filling in skutterudites for thermoelectric applications
Date of Issue2011
School of Materials Science and Engineering
In recent years, skutterudites have attracted huge attention and are reckoned to be one of the most promising groups of thermoelectric (TE) materials due to their “phonon-glass electron-crystal” (PGEC) property facilitated by an open structure in which foreign filler atoms can fill in. In this thesis, we focus on the study of the single and double filling effects on both electrical and thermal properties of skutterudites for thermoelectric applications. La, Ca and Sr were chosen as the filler atoms for the single filled skutterudites, while Ca-La and Sr-La were selected as the dual filler atoms for the double filled skutterudites. In addition, Fe was doped in the Co sites to create holes and thus compensate the extra electrons due to the introduction of these filler atoms. The electrical properties such as the Seebeck coefficient and electrical resistivity were measured as a function of temperature from 5K to 800K, and the electrical power factor was calculated. The temperature dependence of the total, electronic and lattice thermal conductivity were evaluated. Based on these properties, the dimensionless figure of merit, ZT, which is the standard parameter to estimate the TE performance and efficiency, was determined.