Mechanical and surface properties of Aluminum-Copper-Iron quasicrystal thin films.

We show quasicrystal formation by annealing multilayers of Al, Cu and Fe. The mechanical and surface properties of quasicrystals are affected by the parameters of annealing process. Here, multilayer Al-Cu-Fe thin film samples with different compositions were sputtered on Si/SiO 2 substrates and subjected to a two-step annealing process for different durations (5, 10 and 15 h). X-ray diffraction analyses indicated that the 15-h annealed sample had a sharper quasicrystal peak, which was more stable than any other phases. From the XRD data, the amount of each phase was calculated; the sample with longer annealing duration revealed a high amount of ψ-phase (84.3% crystallinity of quasicrystal) with a small amount of cubic Al 50 (CuFe) 50 phase. Nanoindentation tests and contact angle measurements showed that this sample also had the greatest hardness (∼11 GPa) and the highest contact angle (127°), respectively. [ABSTRACT FROM AUTHOR]