STRUCTURE OF CO LAYERS IN CO CU MULTILAYERS AT THE FIRST ANTIFERROMAGNETIC MAXIMUM STUDIED BY NUCLEAR-MAGNETIC-RESONANCE/

Using Co-59 nuclear magnetic resonance, a structural study has been pe rformed on a series of Co/Cu multilayers with Cu thickness of 9 Angstr om (corresponding to the first maximum of antiferromagnetic coupling) and Co thickness varying between 10 and 50 Angstrom. The structure of the Co layer is fee for small Co thicknesses. With increasing Co thick ness, a rapid increase of hcp Co content is observed, particularly for samples between 10 and 30 Angstrom Co. The equivalent thickness of th e deposited Co involved in the mixed interface planes is estimated to be a total of about 5 Angstrom for both interfaces of the Co layer. Th e interface maintains a relatively sharp concentration profile similar to that observed in samples at the second maximum of antiferromagneti c coupling. However, a certain degree of topological disorder in the i nterface is introduced by the onset of hcp stacking. (C) 1997 American Institute of Physics.