Energy and volume expansion in Ag ½¯110 STGB

The energies of ½¯110 STGB have been calculated with MAEAM for a series of 44 GBs in FCC metal Ag. They are unrealistically high for the two crystals rigid joined together, this is caused by the atoms near GB plane are very close so that they will repel each other and result in a GB expansion and energy decreasing. The minimum energy after expansion Emin depends on rotation angle u, four lowest energies are corresponding to (1 1 1) (u = 70.538), (1 1 3) (u = 129.528), (3 3 1) (u = 26.538) and (1 1 2) (u = 109.478) GB successively. Considering minimization of the energy, these four boundaries should be preferable in (h h k) GB. It is found that the lowest-energy GB corresponds to the smallest volume expansion dV and miscoordination coefficient C(m) successively. The former is consistent with the results of rotating sphere-on-a-plate experiments. In addition, the minimum GB energy Emin increases linearly with increasing excess volume dV.