Abstract
TiFe0.5Ni0.5Sb-based half-Heusler compounds have the intrinsic low lattice thermal conductivity and the adjustable band structure. Inspired by the previously reports to achieve both p- and n-type components by tuning the ratio of Fe and Ni based on the same parent TiFe0.5Ni0.5Sb, we selected Co as the amphoteric dopants to prepare both n-type and p-type pseudo-ternary Ti(Fe, Co, Ni)Sb-based half-Heusler alloys. The carrier concentration, as well as the density of states effective mass was significantly increased by Co doping, contributing to the enhanced power factor of 1.80 mW m−1 K−2 for n-type TiFe0.3Co0.2Ni0.5Sb and 2.21 mW m−1 K−2 for p-type TiFe0.5Co0.15Ni0.35Sb at 973 K. Combined with the further decreased lattice thermal conductivity due to the strain field and mass fluctuation scattering induced by alloying Hf on the Ti site, peak ZTs of 0.65 in n-type Ti0.8Hf0.2Fe0.3Co0.2Ni0.5Sb and 0.85 in p-type Ti0.8Hf0.2Fe0.5Co0.15Ni0.35Sb were achieved at 973 K, which is of great significance for the thermoelectric power generation applications.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.