Thermal stability of a Co/Cu giant magnetoresistance (GMR) multilayer system

As revealed by the WATAP analysis, Co breakthroughs along grain boundaries in the Cu spacers appear at 450 °C. This morphological change leads to a deterioration of the GMR effect due to the magnetostatic ferromagnetic coupling between Co layers. Furthermore, a strong effect of Cu layers faceting is observed after annealing in the same temperature range, which may lead to the deterioration of the layered structure on high-angle grain boundaries.