Preparation of Al-Cu-Fe ultra-thin quasicrystalline films without protective coatings by MBE: influence of processing

This study presents a process for making ultra thin films of icosahedral Al-Cu-Fe alloy with a free surface. Three independent evaporation guns were chosen for each of the three elements and were operated under ultra-high vacuum. Thick films (100 nm) made by the classical successive deposition method followed by annealing yield a significant roughness. Thus, it is impossible to study the physico-chemical and optical properties of the surface of this type of deposit. This study shows that the simultaneous deposition of the three elements results in homogeneous quasicrystalline deposits with a roughness ten times lower than with the successive deposition method.