AB-INITIO CALCULATIONS OF METAL CERAMIC INTERFACES - WHAT HAVE WE LEARNED, WHAT CAN WE LEARN/

We discuss the recent first principles calculations of the properties of interfaces between metals and oxides. This type of calculation is p arameter-free, und exploits the density functional theory in the local density approximation to obtain the electronic structure of the syste m. At the same time the equilibrium atomic structure is sought, which minimises the excess energy of the interface. Up to now calculations o f this type have been made for a few model interfaces which are atomic ally coherent, that is with commensurate lattices. Examples are Ag/MgO and Nb/Al2O3. In these cases it has been possible to predict the stru ctures observed by high resolution electron microscopy. Besides the el ectronic structure of the interface, such calculations have provided v alues of the ideal work of adhesion. Electrostatic image forces in con junction with the elementary ionic model provide a simple framework fo r understanding the results.