Evidence for Two Current Conduction in Iron

TL;DR

This paper provides the first experimental evidence of two parallel current conduction channels in ferromagnetic iron alloys, supporting the theory of impurity shielding and explaining deviations from Matthiessen's rule.

Contribution

It demonstrates the existence of spin-dependent conduction channels in iron alloys, a foundational insight for understanding giant magnetoresistance phenomena.

Findings

Strong deviations from Matthiessen's rule observed

Consistent with impurity shielding theory

Supports two-current conduction model

Abstract

Measurements of resistivities of dilute iron based alloys show strong deviations from Matthiessen's rule. These deviations can be explained by a model in which spin up and spin down electrons conduct in parallel. The results are consistent with the theory of impurity shielding in these alloys. [This 1967 paper provides the first experimental demonstration of two current conduction at low temperatures in a ferromagnetic metal. One direct consequence of this property is the Giant Magnetoresistance discovered in 1988 by the groups of Albert Fert and of Peter Gr\"unberg].