In order to identify interdiffusion and microstructural changes in sputtered 90nmCo/180nmCu/90nmCo trilayers during annealing, evolution of the stress and electrical resistance was studied in situ during temperature ramping and isothermal annealing. Concentration-depth profiles, grain morphology and phase and texture formation were investigated after heat treatment at various temperatures. No distinct lattice interdiffusion was observed at up to 450C. The grain-boundary diffusion of Cu through the Co top layer to the surface, as well as the distinct growth of Cu grains into the Co top layer, started to occur at about 450C. The conclusions confirmed results, for

Cu/Co nanoscale multilayers, which revealed a deterioration of the giant magnetoresistance effect at high temperatures; due to similar microscopic mechanisms.

Interdiffusion, Stress, and Microstructure Evolution during Annealing of Co/Cu/Co Trilayers. W.Brückner, S.Baunack, J.Thomas, M.Hecker, C.M.Schneider: Journal of Applied Physics, 2002, 91[12], 9696-700