New structures and atomistic analysis of the polymorphism for the Σ=5 (210) [001] tilt boundary

Using interatomic potentials derived from the second moment approximation of the tight-binding scheme, we study the relative stabilities for the different structures of the Sigma = 5 (210) [001] tilt boundary in Cu and Ag. Relatively to the numerous previous studies, we obtain two new structures characterised by a larger periodicity along the tilt axis. Depending on the metal and on subtle features of the potentials, we show a very significant evolution of the relative stabilities. Using a local analysis on the different sites of the grain boundary, we link the stability of a given structure to peculiar features of the interatomic potential and to physical properties of the metal.