Defects in the Grain Boundary Structure

Abstract

As there exists an equilibrium concentration of vacancies or self-interstitials in a crystal at any temperature, causing an increase in internal energy, there is also an equilibrium concentration of these defects in a grain boundary. No technique enables to directly reveal these defects owing to the low concentration of atoms in the grain boundary core. However, simulations of grain boundaries in which point defects have been introduced lead to relaxed intergranular structures containing such defects. The energy attached to each site and to each type of defect (vacancy, interstitial) differs from one situation to the other, resulting in a large number of possible configurations [1-3].