Interface reconstruction and dislocation networks for a metal/alumina interface: anatomistic approach

Abstract

Misfit dislocation is an important component of the semi-coherent interface.Usually, it forms a dislocation network as the strain concentration areaon an interface and makes the other part coherent. This is the regularcase, but there are also some exceptions. In this work, we show that theNi/(Al2O3)Al interface has a reconstruction at the first monolayer of themetal side, which works as a transition layer between Ni andAl2O3 lattices. Under these conditions, the misfit dislocation cannot be confirmed by drawing aBurgers circuit because the interface is incoherent. However, due to the lattice misfit, thereare areas of strain concentration and areas without strain distributed on the interfaceplane. So, for describing this strain distribution, we again use the concept of a dislocationnetwork but redefine it as the separate line between these two parts. As a result, we findthat the dislocation network appears when the metal part is thicker than 12.4 Å, and itshrinks as the metal film grows, resulting in an ultimate structure with a mesh size of 28.1 Å.