Measurement of roughness and diffuseness of interfaces

We propose a simple formalism which allows the separation of the contributi ons, due to roughness and chemical interdiffusion, to the total width of an interface by using two-dimensional information from either images or chemi cal maps. A definition is also proposed for the roughness of an interface i n terms of iso-concentration surfaces. The formalism is based on the relati on between projection in real space and the corresponding section in Fourie r space, the main hypotheses being that the interface roughness is isotropi c and that the composition profile is constant along the interface. The met hod, although general, will be illustrated with results on Fresnel imaging of Cu-Co magnetic multi-layers. (C) 2000 Elsevier Science B.V. All rights r eserved.