CPM Seminar

New Materials based on Interface Engineering

George Sawatzky

Advanced materials and process engineering Laboratory
Department of Physics
University of British Columbia

The properties of materials are determined by the electronic structure which in turn depends strongly on chemical composition and the crystal structure. Things may become even more interesting at the surface or at an interface of a material because of the very strong dependence of the properties on the lattice constant and the crystallographic orientation of the surface. Using modern material preparation methods such as molecular beam epitaxy one can prepare materials in thin film form of only a few atoms thick and build up multilayers who's properties will be determined by the interfaces rather than the bulk properties of the components. In this way completely new classes of materials with exotic properties can be made. In this small length scale limit quantum mechanics dominates in determining the electronic structure and physical properties. Several examples of the strong influence of the interface will be discussed including organic molecular systems as well as simple oxides and transition metal oxides. I will use modern electron spectroscopic techniques to study some model systems and theory based on density functional theory (LDA+U) as well as model Hamiltonian studies to calculate the electronic structure. The goal is to predict pathways towards new materials based on interface engineering especially for device applications.