Segregation and strain relaxation in Au/Ni multilayers: An in situ experiment

We report on in situ real-time measurements of both stress and strain durin g growth of ultrathin layers, with submonolayer sensitivity. The in-plane l attice parameter is measured by reflection high energy electron diffraction and the stress is determined via the curvature measurements. The system st udied is Au/Ni (i.e., Au on Ni and Ni on Au). We have evidenced a large asy mmetry in the two different growths: Au (on Ni) shows a progressive elastic strain relaxation, whereas Ni (on Au) exhibits a strong interplay between the stress and the interfacial mixing. (C) 1999 American Institute of Physi cs. [S0003-6951(99)00733-0].