ELECTRICAL RESISTIVITIES OF AL-PD-MN ICOSAHEDRAL QUASI-CRYSTALS

The resistivity of Al-Pd-Mn icosahedral quasicrystals increases almost linearly with decreasing temperature, shows a maximum at a temperature (between 10 and 100 K) and then decreases in low Mn alloys (<9at%Mn), while in high Mn alloys (>9at%Mn) the resistivity increases again steeply at even lower temperatures. The resistivity at helium temperature varies from 1500 to 9500 muOMEGAcm depending on the composition and quasicrystallinity of the sample. The magnetoresistance in single-grained sample of Al70Pd21Mn9 is positive and temperature dependent, with DELTA rho/rho at 0.5 K at 8 T being as large as 6%. It is concluded that the temperature and magnetic-field dependences are governed dominantly by the weak localization effect for the case of strong spin-orbit scattering, and in high Mn concentration alloys, a Kondo effect superimposes to the weak localization effect.