Low-temperature conductivity and magnetoconductivity of icosahedral Al70Mn9Pd21

Abstract

Measurements of the electrical conductivity and magnetoconductivity are reported for icosahedral Al70Mn9Pd21 at low temperatures. Above 1 K, the σ(T) variation is consistently described by a sum of weak-localization and Coulomb-interaction terms. Below 1 K, the conductivity varies as σ(T) = σ(0) + a√T which may entirely be ascribed to a Coulomb-interaction correction. In this regime, the magnetoconductivity is positive. For magnetic fields up to 45 kOe, σ(T) keeps its √T-dependence. The parameter a decreases with magnetic field, which contradicts theoretical expectations.