Modeling of complex interfaces: Gadolinium‐doped ceria in contact with yttria‐stabilized zirconia

Gadolinium‐doped ceria (GDC) and yttria‐stabilized zirconia (YSZ) are well‐known electrolyte materials in solid oxide fuel cells (SOFCs). Although they can be used independently, it is common to find them in combination in SOFCs, where they are used as protective layers against the formation of secondary phases or electron conduction blockers. Despite their different optimum operating temperatures, it appears that oxygen conduction is not affected by their interface. However, the intrinsic mechanisms of oxygen diffusion at these interfaces still remain unclear. One of the main difficulties when modeling the contact between different materials, or indeed different particles of the same material, is caused by the structural complexity of these systems. If we wish to evaluate the properties of the materials, we first need to obtain a model that includes the main features of the GDC/YSZ interface, such as large‐scale defects or cation interdiffusion in the contiguous phase. Since the generation of such a mixed system is complicated, we show here how the “amorphization and recrystallization” strategy can help us to obtain realistic systems. In this, the first of our papers on the structure and properties of layered GDC/YSZ materials, we discuss the structural features of the grain boundary between GDC and YSZ obtained by molecular dynamics simulations.