A dodecagonal quasicrystalline phase was grown in nano-sized Ag-Pt multilayers upon solid-state reaction and the existence of the respective metastable state in the Ag-Pt system was also confirmed by ion-beam mixing experiments. The major driving force for intermixing between the nano-sized Ag and Pt layers, as well as for the crystal-to-quasicrystal transition, was thought to be the interfacial free energy, which elevated the initial Ag-Pt multilayers up to an energetic state corresponding to the dodecagonal phase.

Abnormal structural changes were observed in the equilibrium immiscible Co50Cu50 multilayers induced by 200 keV xenon-ion irradiation at 77 K. First, a dodecagonal quasicrystal phase was formed at an irradiation dose of 1×1015 Xe+ cm-2. Secondly, series of selected diffraction patterns taken later showed that the dodecagonal phase formed evolved to feature a high degree of ordering with increasing ion dose. Moreover, molecular dynamics simulations verified the possibility of formation of a metastable phase in the Co-Cu system. A mechanism possibly responsible for the observed structural changes upon ion irradiation is also discussed.