Effect of Annealing on Interface Structure and Giant Magnetoresistance Oscillation in Co/Cu Multilayers

Abstract

The effect of annealing on the oscillatory behavior of giant magnetoresistance (GMR) is studied in Co/Cu multilayers. Annealing at 200° C in vacuum reduces the height of the 1st peak of GMR oscillation significantly. However, the degradation of interface measured by X-ray diffraction is not large compared with the change in GMR. Microscopic change of the interface state causes ferromagnetic interlayer coupling between adjacent Co layers and diminishes the 1st GMR peak. The 2nd GMR peak, on the other hand, is not so sensitive to the degradation of the interface.

Analysis of the interfaces of and multilayers

“…It is widely accepted that the spin dependent electronic scattering at the interface plays an important role in defining the GMR effect. Previous studies on the role of the interface roughness on the GMR have been conducted by several authors [2,3]. The rms of the interfacial roughness consists of both geometrical and intermixing parts [4,5], but they will have different contributions to the GMR.…”

Étude des interfaces enterrées par diffraction de rayons X

“…Nawate [59] a par exemple essayé de déteminer si les changements de magnéto résistance dans les multicouches ColCu après un recuit à 200°C affectait la rugosité d'interface. En fait les changements vus en rayons X sont très faibles et la dégradation des propriétés magnétiques est attribuée à des réarrangements très locaux dont les déplacements moyens vus par rayons X sont insignifiants.…”