Molecular dynamics simulation of crack tip processes in ceria and gadolinia doped ceria

摘要

Fracture behaviors in ceria and gadolinia doped ceria are simulated by molecular dynamics utilizing an in-home potential. The effects of temperature, lattice orientation and doping content are taken into consideration. When no dopant is introduced, for cracks on the (0 0 1) and (01?1) plane, the crack propagates with local plastic deformation, and no obvious dislocation emissions are observed; for crack on the (1 1 1) plane, the slippage can be found during the process. In the contrast, when dopant is introduced, brittle fractures are observed for all models, meanwhile, the critical stresses are reduced. In addition, with the increase of temperature, only critical stresses of crack propagation are reduced, the fracture mechanisms are almost unchanged for all models.