Evaluation of the contribution of the mean free path in Co to the magnetoresistance in Co/Cu multilayers

Abstract

The mean free path (MFP) within the Co layer is systematically varied between 10 Å and 500 Å. This variation allows for the investigation of its effect on the current-in-plane magnetoresistance (MR) of Co/Cu angstrom-scale multilayers. The study also explores the influence of surface roughness on the magnetotransport properties of these structures. To analyze the role of interfacial features, two interface configurations are examined: one with a smooth interface and the other with a rough interface. This comparative study highlights how interface quality impacts the magnetic behaviour of the multilayers. Numerical simulations show that MR decreases with MFP for smooth interfaces but may either increase or decrease with MFP for rough interfaces, depending on the electron spin diffusion mechanisms at the Co/Cu interface. The magnitude of MR is strongly dependent on surface roughness, with variations in interfacial characteristics leading to significant differences in MR behaviour. These results emphasize the critical role of both interface quality and surface roughness in determining MR characteristics.