Structural, magnetic and magneto‐transport properties of thermally evaporated Fe/Cu multilayers

Abstract

Structural, magnetic and magneto-transport properties of thermally evaporated Fe/Cu multilayers (MLs) have been investigated. Although multilayered structure has been successfuly obtained, a substantial interfacial roughness ranging from 0.6 nm to 1.2 nm has been determined. All Fe/Cu MLs were polycrystalline with an average grain size of about 10 nm. Fe was bcc and textured (110) whereas Cu was fcc (111). Transmission electron microscopy analysis showed that the fcc Cu layer was rather textured (110) and (100) at least in the first stage of growth of the Fe/Cu MLs. Conversion electron Mössbauer (CEMS) measurements indicated the existence of three phases. Two of them were magnetic with a dominant bcc Fe phase, followed by fcc Fe phase. The third phase was superparamagnetic. The CEMS results were explained in terms of the partial diffusion of Fe into Cu with three different zones. The small magnetoresistance (MR < 0.2%) was correlated to Fe clusters located at Fe–Cu interfaces.