Anomalous electronic transport inξ′-Al–Pd–Mn complex metallic alloy studied by spectral conductivity analysis

Abstract

The ξ′ giant-unit-cell phase of the Al–Pd–Mn alloy system exhibits an almost temperature-independentelectrical conductivity with a value typical of metallic alloys, but an anomalously lowthermal conductivity comparable to that of thermal insulators. The origin of theT-independent conductivity is analysed by determining the spectral conductivity functionσ(E) from a combined analysis of the electrical conductivityσ(T) and thethermoelectric power S(T) using a phenomenological approach. It is found that theT-independence of the conductivity results from the specific form of the spectralconductivity, which shows very weak variation over an energy scale of severalkBT around the Fermi level, but exhibits fine structure that yields observable effects inσ(T) and S(T).