The structure and phase composition of Co/Cu bilayers: sensing elements for magnetoresistive application

Experiments were carried out on single films of Co and Cu, and on Co-Cu bilayers evaporated on the NaCl(001) substrates at room temperature. A thickness of single films, measured by interferometry method, has been changed from 3 to 40 nm for Cu and from 5 to 40 nm for Co. The Transmission Electron Microscope studies showed that at annealing temperatures below 600 K the films consist of fcc Cu and hcp Co. After annealing at higher temperatures, besides the presence of phases already observed at lower temperatures, also Co-Cu solid solution together with single phase of hcp Co was observed.