Dresden 2003 – wissenschaftliches Programm
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M: Metallphysik
M 29: Nanoskalige Materialien III
M 29.3: Vortrag
Mittwoch, 26. März 2003, 15:15–15:30, IFW A
Three-dimensional atomprobe investigation of Al/Co thin film reaction — •Vitaliy Vovk1 and Guido Schmitz2 — 1Institut für Materialphysik, Hospitalstr. 3-7, 37073 Göttingen — 2Institut für Materialphysik, Wilhelm-Klemm-Str. 10, 48149 Münster
With increasing miniaturization and development of nano-technology, initial stages of reactive diffusion attract particular interest. A two stage reaction mechanism was proposed to explain double-peaked heat releases in the DSC traces obtained for some thin film reaction systems (Ni/Al, Ti/Al, Co/Al). In order to obtain detailed information we investigated the reaction in Al/Co thin film system with the 3D atomprobe, which has been proven to yield a chemical analysis with single atom sensitivity. By direct chemical analysis we proved the following steps: 1. Formation of solid solution zone up to 4 nm width. 2. Heterogeneous nucleation of Al9Co2-phase. 3. Rapid growth of nuclei by incoherent phase boundary transport resulting in particles of up to 10 nm width (corresponding to first heat release in DSC-traces). 4. Formation of a closed layer of Al9Co2-phase and diffusion controlled thickening until consumption of pure Al (second heat release in DSC-traces).