Thermoelectric properties of polygrained icosahedral Al71−xGaxPd20Mn9 (x=,2,3,4) quasicrystals

Abstract

The electrical and thermal transport properties of quaternary icosahedral Al71−xGaxPd20Mn9 (x=0,2,3,4) quasicrystals, obtained by replacing Al in icosahedral Al–Pd–Mn quasicrystal with Ga, have been measured in accordance with the guiding principle of “weakly bonded rigid heavy clusters” (WBRHCs). While the electrical conductivity and Seebeck coefficient were not dramatically changed, the thermal conductivity effectively decreased with increasing Ga concentration except for the sample with x=4. Although the thermoelectric properties do not obey the WBRHCs, the dimensionless figure of merit increased by a factor of 1.4 from 0.18 for Al71Pd20Mn9 to 0.26 for Al68Ga3Pd20Mn9 quasicrystal.