Computer simulations were used to investigate the stability of typical dislocations in uranium dioxide. The methods used to produce the dislocation configurations and calculate the line energy and Peierls barrier for pure edge and screw dislocations with the shortest Burgers vector, ½<110>, . The easiest slip system was found to be the {100}<110> system for stoichiometric UO2, in agreement with experimental observations. Attention was also paid to the various strain fields associated with these line defects, and the close agreement between the strain field predicted by atomic scale models and the application of elastic theory. Molecular dynamics simulations were used to investigate the processes of slip that might occur for the three different edge dislocation geometries and nudged elastic band calculations were used to establish a value for the Peierls barrier, showing the possible utility of the method in investigating both thermodynamic average behaviour and dynamic processes such as creep and plastic deformation.

Strain Fields and Line Energies of Dislocations in Uranium Dioxide. D.C.Parfitt, C.L.Bishop, M.R.Wenman, R.W.Grimes: Journal of Physics - Condensed Matter, 2010, 22[17], 175004