Affordable Access

Publisher Website

Insulator-like electrical transport in structurally ordered Al65Cu20+ xRu15− x(x = 1.5, 1.0, 0.5, 0.0 and −0.5) icosahedral quasicrystals

Journal of Non-Crystalline Solids
Publication Date
DOI: 10.1016/j.jnoncrysol.2004.11.005


Abstract Low-temperature resistivities, in zero-field and 8 T field, and magnetoresistance have been measured down to 1.4–300 K for stable icosahedral quasicrystals Al 65Cu 20+ x Ru 15− x ( x = 1.5, 1.0, 0.5, 0.0 and −0.5). The analysis of the magnetoresistance data shows an overwhelming presence of anti weak-localization effect ( τ so ∼ 10 −12 s). But the sample with x = −0.5 shows anomalous magnetoresistance and the anti weak-localization effect breaks down ( τ so to be 10 −15 s). The in-field σ– T between 5 K and 20 K, for x = 1.0, 0.5, 0.0 and −0.5 samples, and between 1.4 K and 40 K for x = 1.5 sample, follow a power-law behavior with an exponent of 0.5 and above ∼30 K the exponent ranges from 1.17 to 1.58. The observed power-laws basically characterize the presence of critical regime of the metal–insulator (MI) transition, dominated by electron–electron and electron–phonon inelastic scattering events respectively. In samples with x = 1.0, 0.5, 0.0 and −0.5 the in field σ– T has been found to follow ln σ-vs- T 1/4 below 5 K, which indicates the presence of variable range hopping. The observed transport features indicate the occurrence of proximity of metal–insulator transition in these Al–Cu–Ru quasicrystal samples.

There are no comments yet on this publication. Be the first to share your thoughts.