Insulating icosahedral AlPdRe with resistance ratios $R[=\rho \left(4.2\mathrm{K}\right)∕\rho \left(295\mathrm{K}\right)]$ from 40 to 220 has been studied by magnetoresistance and conductivity measurements. Consistent results for the localization length $\xi$ and the characteristic temperature $T_o$ were determined. $(R-R_c)$ increases from the metal insulator transition (MIT) into the insulator as the inverse of the shrinking volume of the electron wave functions $\sim {\xi }^{-3}$. Localization is driven by disorder. Evidence is discussed that the MITs in $i$-AlPdRe and doped semiconductors belong to the same universality class.

• Received 21 October 2004

DOI:https://doi.org/10.1103/PhysRevB.71.012202