Abstract
A mirror-glide symmetric structure is observed at the Σ = 9 [011̄]/(122) symmetric tilt grain boundary in Cu. No mirror symmetric unit is found which is consistent with the fact that the mirror symmetric unit is relatively higher energy in low stacking fault energy, or higher bulk modulus, fcc metals. The boundary width is estimated to be about 0.1241 nm which is about twice of {224} lattice spacing. © 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All right reserved.