Anomalous transport behavior of a binary Cd-Yb icosahedral quasicrystal

Electronic properties of the recently discovered binary Cd-Yb icosahedral(i) phase have been found to be strikingly different from those of ternary i-phases studied so far: The resistivity decreases rapidly (by 10-80% depending on the composition) with decreasing temperature down to about 10 K and levels off below 10 K. A giant magnetoresistance reaching as high as 200% at 9 T is observed at low temperatures. The electronic specific heat coefficient γ is very large, i.e., 2.87 mJ/(mole·K²), and the Debye temperature Θ_D is as low as 140 K, which are in striking contrast with the trend observed in ternary i-phases. These anomalous features indicate that a different transport mechanism other than those proposed for ternary i-phases has to be considered for the present binary i-phase.