Year-end Sale % OFF 
Abstract
Skutterudites are known as excellent thermoelectric p- and n-type materials and have already achieved good efficiencies for the conversion of heat to electricity, but nevertheless researchers try to further enhance the figure of merit, ZT. In the present work the aim was to mix p- and n-type skutterudite powders with additives in order to produce an evenly dispersed distribution of sub micron grains, preferable small nano-particles, which enhance the scattering of the heat carrying phonons of different wavelengths and reduce thermal conductivity without changing electrical resistivity and Seebeck coefficient. Various quantities of three groups of materials (a) nonmetallic oxides (Al2O3), (b) metallic oxides (Cu2O and La1.85Sr0.15CuO4) and (c) metallic borides (Fe2.25Co0.75B and Ta0.8Zr0.2B) were added to industrially produced p-type (DDyFe3CoSb12) and n-type ((Mm,Sm)yCo4Sb12) skutterudite powders. First the influence of pre-sieving and various ball milling conditions before hot pressing were studied, using Al2O3 as additive. As a consequence of these studies pre-sieved powders and high-energy ball milling were used for all following experiments. The goal, to enhance ZT was not reached with Al2O3 and Cu2O. La1.85Sr0.15CuO4 was successful for the n-type, Fe2.25Co0.75B for the p-type skutterudites, although ZT-enhancement was small, but with Fe2.25Co0.75B the maximum ZT could be shifted to lower temperatures, a valuable information for device production. Much better results in respect to ZT values were gained with adding 0.5, 1.0 and 1.5 wt.% Ta0.8Zr0.2B to p-type DDyFe3CoSb12. In this series it was possible to enhance ZT (from ZT ∼ 1.2 to ZT ∼ 1.3) as well as to significantly increase the thermal-electrical conversion efficiency η. In addition, we found that all boride additives enhanced the hardness, elastic moduli and fracture resistance.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
