High strength, epitaxial nanotwinned Ag films

Epitaxial silver films with (1 1 1) and (1 1 0) orientations were deposited by magnetron sputtering onto silicon (1 1 1) and (1 1 0) sub strates, respectively High density growth twins with an average spacing of a few nanometers are observed in the (1 1 1) oriented films, with twin boundaries oriented normal to the growth direction Twins are observed in the (1 1 0) oriented films with a much lower twin density, and the twin boundaries are oriented 60 degrees from the growth direction The epitaxial nanotwinned Ag (1 1 1) and (1 1 0) films have respective indentation hardness values of similar to 2 and 1 GPa The influences of deposition parameters, stacking fault energy, and orientation of {1 1 1} planes on the formation of nanotwins are discussed (C) 2010 Acta Materialia Inc Published by Elsevier Ltd All rights reserved