Mechanism of texture development in ion-beam-assisted deposition

We perform a series of atomistic simulations of ion-beam-assisted deposition (IBAD) to identify the mechanism by which ion beams select crystallographic texture. Simulations were devised to distinguish between two previously proposed mechanisms: (1) preferential sputtering of differently oriented grains and (2) preferential damage of differently oriented grains followed by grain-boundary migration. We show that while preferential sputtering is capable of producing texture change, it does so much more slowly than observed in IBAD. Simulations that include only differential damage produce structures which are nearly indistinguishable from those seen in IBAD. These results conclusively demonstrate that texture evolution during ion-beam-assisted deposition is dominated by differential damage and subsequent recrystallization.