Abstract
The binary Al–Ir 1/0 quasicrystalline approximant is predicted to be a narrow band gap semiconductor with a large Seebeck coefficient; however, it has not yet been realized practically because the presence of Al vacancies causes excess hole doping, which results in a small Seebeck coefficient. Here, we synthesized and measured the true density, lattice constant, and thermoelectric properties of Al-(Rh,Ir) quasicrystalline approximants with a series of Al73.3(RhxIr1-x)26.7 (x = 0, 0.25, 0.5, 0.75, 1.0) compositions. The number of atoms per unit cell calculated using the true density, nominal composition, and lattice parameter increased with increasing Rh content x. The compositional dependence of the Seebeck coefficient and dimensionless figure of merit zT showed a maximum value at x = 0.25, 850 K. The results indicated that Rh doping could effectively suppress Al vacancies, and the width of the band gap decreased with increasing x. In other word, a trade-off was observed between the amount of Al vacancies and the width of the band gap between the Al–Ir and Al–Rh 1/0 quasicrystalline approximants.
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.
