Peculiarities of Intermetallic Phase Formation in the Process of a Solid State Reaction in (Al/Cu)(n) Multilayer Thin Films

Phase formation in a solid state reaction in Al/Cu bilayer and multilayer thin films was studied by the methods of in situ transmission electron microscopy, electron diffraction, simultaneous thermal analysis and x-ray diffraction. It was established that the phase formation sequences in the (Al/Cu)n (n = 2, 15) multilayer thin films (θ-Al2Cu → γ1-Al4Cu9 → η2-AlCu) and Al/Cu bilayer thin films (θ-Al2Cu → η2-AlCu → γ1-Al4Cu9) were different. It was assumed that the phase formation process in the thin films was strongly affected by a number of copper/aluminum interfaces due to the changes of aluminum and copper diffusion current.