Plastic deformations of ceria nanocubes under compression: An atomistic simulations study

Abstract

The mechanical properties and elementary deformation processes of ceria nanoparticles are investigated under uniaxial compression using quasi-static atomistic simulations and a fixed charge empirical potential. Results show a strong size-dependence of both the stress response and the plastic deformation phenomena that are characterized by amorphization and recrystallization processes that initiate from the surfaces in smaller-size samples, while the propagation of {111} nanotwins is observed in larger nanoparticles. In particular, we point out that the recrystallized phase is made of reoriented fluorite that behaves as a structural seed for the nucleation of 16<112>{111} partial dislocations at the origin of the nanotwins. Similarities with plastic deformation processes of FCC metals at the nanoscale are outlined and discussed.