Structural Studies of Co/Cu and Co/Ru Interfaces Using $\text{}^{59}$Co NMR Method

The structural and magnetic properties of three magnetron sputtered multilayers at the 2nd maximum of antiferromagnetic coupling were studied using $\text{}^{59}$Co NMR spectroscopy: [Co(20 Å)/Cu(20 Å)]$\text{}_{20}$, [Co(20 Å )/ Ru(18 Å)]$\text{}_{20}$ and a heterostructure, in which non-magnetic spacers alternated between Cu and Ru. Co/Cu interfaces were found to be relatively sharp, extended over 3 monolayers, while the Co/Ru interfaces extend over 6 monolayers due to the good miscibility of Co and Ru. The NMR restoring field in the heterostructure is found to be the average of the restoring fields in both reference samples.