ENERGY OF (110)TWIST BOUNDARIES IN AG NI AND ITS VARIATION WITH INDUCED STRAIN/

The energy of (110) twist boundaries in the Ag/Ni system, as a functio n of twist angle, has been calculated using the embedded atom method ( EAM). Two major cusps appear at 0 degrees and 54.74 degrees in additio n to some less prominent cusps, including 35.26 degrees and 70.53 degr ees. The variation of the boundary energy with coincidence strain has been studied. It is shown that calculations with small coincidence str ains, up to about 2%, yield reasonable approximations to the energy of the strain-free interface. Perturbing the initial atomic positions in the two crystals significantly reduces the energy associated with som e special boundaries, one of which is the 54.74 degrees boundary. This is shown to be a consequence of a reconstruction of the boundary that is not accessible to the unperturbed crystals.