Localized grain-boundary electronic states and intergranular fracture.

The appearance of localized grain-boundary electronic states is shown to provide a reliable indication of intergranular fracture in polycrystalline materials. Representative densities of states are presented for some L1/sub 2/ intermetallic compounds by use of polyhedral models of grain-boundary structure. The role of certain segregated impurities as inhibitors of intergranular brittleness is briefly discussed and suggestions are made for direct experimental verification of our model.