NMR study of the strain in Co-based multilayers

The strain in Co layers of multilayers with largely different structural mismatch (Co/Ni, Co/Ag, and Co/Cu) has been measured with nuclear magnetic resonance and compared with a model for strain in multilayers that is based on the model of Van der Merwe and Jesser. For the Co/Ni multilayers, the measured strain depends on both the Co and the Ni layer thicknesses over a large range and follows the behavior expected from the model in the coherent regime. The strain in the Co/Ag multilayers is proportional to 1/tCo and independent of the thickness of the Ag layers. This behavior resembles that for the incoherent regime. For Co/Cu multilayers the results indicate that the multilayers are in the transition region from coherent to incoherent behavior.