Ion‐beam‐induced atomic mixing and amorphization in Ti/Ni bilayered thin films

摘要

Ion‐beam‐induced atomic mixing of Ti/Ni bilayers was studied by transmission electron microscopy. The depth of the Ti/Ni interfaces was controlled to be approximately equal to the mean damage depth of 150‐keV Ar ions. At a critical dose of 1×1015 ions/cm2, diffuse halo rings appear in the electron diffraction pattern, and increase in their intensity with Ar dose. This indicates that an amorphous phase is formed by ion mixing of the bilayers. After a high dose of 1×1017 ions/cm2, a high density of Ar bubbles is observed near the interface boundary. These results are understood in terms of the simultaneous operation of ion‐beam‐induced mixing and radiation‐induced lattice instability.