Electrical resistivity of icosahedral Mg-Al-Zn alloys

The temperature and magnetic field dependence of the electrical resistivity has been measured on single-phase icosahedral ${\mathrm{Mg}}_{32}$(${\mathrm{Al}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Zn}}_{\mathrm{x}}$ ${)}_{49}$ at x=0.5 and x=0.69. For temperatures between 4 and 20 K the observed behavior is found to agree quantitatively with the theories of quantum corrections to electron transport in disordered conductors. By fitting the magnetoresistance measurements to these theories, we can determine the resistivity in a way which is independent of the sample geometry, and we find that it shows a remarkably strong dependence on the alloy composition.