Electrical and thermal transport properties of icosahedral Al70Pd22.5„Re1−xMnx...7.5 quasicrystals

This work presents measurements of the electrical resistivity srd, Seebeck coefficient, and thermal conductivity skd of icosahedral Al70Pd22.5sRe1−xMnxd7.5 quasicrystals from 10 to 300 K. A series of quasicrystals was prepared with x=0, 0.1, 0.2, 0.3, 0.5, 0.6, 0.8, and 1.0 to systematically study the effect of substitution. The electrical resistivity increases as the temperature decreases, suggesting a semiconductinglike behavior in these alloys. The room-temperature values of the Seebeck coefficient vary from −5 mV/K to +65 mV/K, showing a significant dependence on the value of x. However, k exhibits a rather weak composition dependence in the temperature range investigated. The room-temperature dimensionless thermoelectric figure of merit sZTd of this system is optimized at x=0.1. With further appropriate heat treatments, high ZT is presumably available at elevated temperatures in the Al70Pd22.5sRe0.9Mn0.1d7.5 sample. © 2005 American Institute of Physics. fDOI: 10.1063/1.1905795g