Magnetoresistance in the region of the possible metal-insulator transitionin icosahedral AlPdRe

The magnetoresistance, Delta rho(B,T)/rho(T), has been measured between 200 mK and 20 K, in magnetic fields up to 12 T for: icosahedral AlPdRe quasicr ystals of nominal composition Al70.5Pd21.5Re8 Samples of varying resistivit ies and residual resistance ratios, R [=rho(4 K)/rho(295 K)], were studied. An analysis of Delta rho(B,T)/rho(T) in terms of quantum interference effe cts (QIE) was made, taking into account the possibility of QIE contribution s to Delta rho(T) up to room temperature. The results show that the regime of diffusive metallic conduction in i-AlPdRe extends up to R in the range o f 20, corresponding approximately to rho(4 K) up to 10(5) mu Omega cm, beyo nd which a description of Delta rho(B, )/rho(T) in terms of QIE breaks down . (C) 1999 Elsevier Science B.V. All rights reserved.