Amorphous and nanocrystalline sputtered Mg–Cu thin films

Binary Mg–Cu amorphous alloys were first fabricated in 1980s via liquid quenching. In this study, the Mg1−xCux (x varying from 38 at.% to 82 at.%) partially amorphous thin films are prepared via co-sputtering. Upon thermal annealing, the Mg2Cu or MgCu2 nanocrystalline phases are induced in the Mg-rich or Cu-rich thin films, respectively. Due to the presence of fine nanocrystalline Mg2Cu or MgCu2 particles in the Mg–Cu amorphous matrix, the as-sputtered thin films show satisfactory Young's modulus ∼100 GPa and hardness ∼4 GPa.