Thick films were sputtered under identical conditions. A wide range of stacking-fault energies (6 to 78mJ/m2) was explored in order to manipulate the twin spacing and microstructure. The Cu-Al samples exhibited highly columnar and nanotwinned grains, while the Cu sample exhibited a limited number of nanotwinned grains. The effects of changes in sputtering rate were also evaluated and compared with theoretical calculations. It was observed that, contrary to predictions, the twin spacing increased at higher sputtering rates.

Influence of Stacking Fault Energy on Twin Spacing of Cu and Cu-Al Alloys. L.Velasco, M.N.Polyakov, A.M.Hodge: Scripta Materialia, 2014, 83, 33-6