Atomic structure of a Σ99 grain boundary in aluminium: A comparison between atomic-resolution observation and pair-potential and embedded-atom simulations

An atomic-resolution image of a symmetrical Σ99 {557} 〈110〉 tilt boundary in aluminium is compared with images simulated from models based on atomistic calculations using pair potentials and the embedded-atom method. The two methods for atomistic modelling result in very similar structures, and image simulations based on these structures closely match the experimental results. This study shows that high-resolution electron microscopy can now be used to assess quantitatively the degree of coincidence between experimental and theoretical atomic structures of high-Σ grain boundaries.