The Metal-Insulator Transition in Al–Pd–Re Quasicrystals

The metal-insulator (M-I) transition in Al–Pd–Re quasicrystals (QCs) was studied by annealing method. We found that increasing the resistivity ratio r =ρ(4.2 K)/ρ(300 K) of Al–Pd–Re QCs can greatly reduce the value of the electron correlation gap Δ and therefore drives the system towards and through the M-I transition. In the insulating state, the conductivity σ( T ) between 0.5∼7 K can be analyzed with σ( T )=σ 0 exp [-( T 0 / T )] 1/4 and the negative magnetoconductance observed at low temperature is mainly attributed to the decrease of the localization length ξ with increasing field.