Atom probe tomography of swift ion irradiated multilayers

Nanometer scale layered systems are well suited to investigate atomic transport processes induced by high-energy electronic excitations in materials, through the characterization of the interface transformation. In this study, we used the atom probe technique to determine the distribution of the different elements in a (amorphous-Fe2Tb 5 nm/hcp-Co 3 nm)20 multilayer before and after irradiation with Pb ions in the electronic stopping power regime. Atom probe tomography is based on reconstruction of a small volume of a sharp tip evaporated by field effect. It has unique capabilities to characterize internal interfaces and layer chemistry with sub-nanometer scale resolution in three dimensions. Depth composition profiles and 3D element mapping have been determined, evidencing for asymmetric interfaces in the as-deposited sample, and very efficient Fe-Co intermixing after irradiation at the fluence 7 × 10 ion cm. Estimation of effective atomic diffusion coefficients Preprint submitted to Elsevier 3 October 2008 ha l-0 02 56 49 8, v er si on 2 3 O ct 2 00 8 Author manuscript, published in "The Seventh International Symposium on Swift Heavy Ions in Matter, Lyon : France (2008)"