Atomistic computer simulation was used to predict the most energetically favourable migration pathways for O ion transport in tetragonal La2NiO4. Both interstitial and vacancy mechanisms were investigated. All of the vacancy mechanisms studied exhibited lower activation energies than the interstitial process. The lowest energy process allowed migration in the a–b plane with an activation energy of 0.35eV, migration along the c-axis was predicted to have an activation energy of 0.77eV and interstitial migration in the a–b plane was found to have an energy barrier of 0.86eV (in agreement with available experimental data).

Atomistic Computer Simulation of Oxygen Ion Conduction Mechanisms in La2NiO4. A.R.Cleave, J.A.Kilner, S.J.Skinner, S.T.Murphy, R.W.Grimes: Solid State Ionics, 2008, 179[21-26], 823-6