Simulations of surfaces and interfaces in MgO

Abstract

Most simulations on surfaces and interfaces consider only the most symmetric cases. However, it is far from clear that these interfaces are representative of the general interfaces seen in practice. For surfaces, the only ceramic systems to be studied are the stepped boundaries derived from surfaces vicinal to the (001) boundaries of MgO and NiO. We have performed an extensive series of simulations to study the interfaces (both surfaces and grain boundaries) for magnesium oxide. The objective here is both to characterise a variety of different kinds of steps on different surfaces and to relate these to the binding energies of grain boundaries. We use the simulations to discuss the general structure of grain boundaries and the adequacy of models based on highly symmetric boundaries for discussing the properties of general boundaries.

Key Words:

• General grain boundary
• Low angle
• Surfaces