First-principles study of ceramic interfaces: SiC grain boundaries and SiC/metal interfaces

摘要

SiC grain boundaries and SiC/metal interfaces have been studied using the ab initio pseudopotential method based on the density-functional theory. The stable configuration of the non-polar interface of the {122}∑ = 9 tilt boundary has been obtained. The tensile strength and fracture of this interface have been clarified through the behaviour of electrons and atoms by using the ab initio tensile test. The Si-terminated and C-terminated SiC(001)/Al and SiC(001)/Ti interfaces have been studied in order to clarify the effects of the surface species and metal species. The four kinds of interfaces have quite different features in regard to atomic configurations, bonding nature, adhesive energy and Schottky-barrier heights.