Proximity of a metal-insulator transition in icosahedral phases of high structural quality

Abstract

High resistivities associated with a reduced density of states and a very low effective number of carriers are measured in high-structural-quality AlCuFe icosahedral phases. These properties vary strongly with composition close to ${\mathrm{Al}}_{63}$${\mathrm{Cu}}_{25}$${\mathrm{Fe}}_{12}$ and suggest that insulating quasicrystals could exist. We also show evidence for quantum interference effects in the measured transport properties and diamagnetic susceptibility.