MISFIT DISLOCATIONS - AN ATOMISTIC AND ELASTIC CONTINUUM APPROACH

This paper presents the results of an atomistic model in which the mis fit and the bond strength between a metal and a substrate can be contr olled. The model is applied to a simple case, i.e. an interface with m isfit in one direction. Calculated energies are presented and the corr esponding atomic structures for various misfits and interaction parame ters are discussed. It turned out that the structure of the misfit dis locations depends both on misfit and bond strength. A trend from deloc alized structures to localized structures that resemble bulk-like disl ocations can be seen for decreasing misfit at constant interaction par ameter, and increasing interaction parameter at constant misfit. This atomistic approach is compared with a description based on linear elas ticity theory of interface dislocations. Although a fair correlation e xists between these two different concepts, it is shown that the elast ic continuum approach cannot account for the possible configurations a t an interface, because it does not contain any information on the eff ects different bond strengths may have on the interface structure. (C) 1997 Acta Metallurgica Inc.