Anomalous electrical conduction in disordered and non-crystalline metallic conductors

Abstract

Many disordered and non-crystalline metallic conductors are characterized by both a negative temperature coefficient ( α = ϱ -1 d ϱ/dT) of resistivity ϱ over a wide range of temperatures T and a gradual leveling-off of ϱ at low temperatures. Experimental results will be presented to show that ϱ varies as -ℓn T (for T ⪸ the Debye temperature) in contrast to the prediction of existing theories. This anomalous electron transport can be understood in terms of an attractive interaction between conduction electrons and localized excitations arising from a structural indeterminacy in the atomic arrangement. The possibility of using this scattering mechanism to explain the unusual deviation from linear T dependence of resistivity (the bulge effect) in many structurally unstable superconductors such as A-15 Nb 3Ge, V 3Si, bcc Nb and alloys containing the ω-phase is also discussed.