Current distribution in metallic multilayers from resistance measurements

Abstract

The in-plane current profile within multilayers of the generic structure Ta/Pt/(CoNi)/Pt/Ta is investigated. A large set of samples where the thickness of each layer was systematically varied was grown, followed by the measurement of the sheet resistance of each sample.

The data are analyzed by a series of increasingly elaborate models, from a macroscopic engineering approach to mesoscopic transport theory. Non-negligible variations of the estimated repartition of current between the layers are found.

The importance of having additional structural data is highlighted.

Keywords

• electrical-resistivity model
• layered magnetic-structures
• spin-orbit torque
• mean free-path
• domain-wall
• polycrystalline films
• surface-roughness
• conductivity
• magnetoresistance
• reflection