Atomic structure of (110) tilt grain boundaries in FCC materials

摘要

High-resolution electron microscopy (HREM) has been used to study the atomic-scale structure and localized relaxations at grain boundaries (GBs) in Au, Al, and MgO. The (110) tilt GBs play an important role in polycrystalline fcc metals since among all of the possible GB geometries this series of misorientations as a whole contains the lowest energies, including among others the two lowest energy GBs, the (111) and (113) twins. Therefore, studies of the atomic-scale structure of (110) tilt GBs in fcc metals and systematic investigations of their dependence on misorientation and GB plane is of considerable importance to materials science. (110) tilt GBs in ceramic oxides of the fcc structure are also of considerable interest, since in this misorientation range polar GBs exist, i.e. GBs in which crystallographic planes that are made up of complete layers of cations or anions can join to form a GB.