The annealing of the B cation interstitial was shown to drive the thermokinetic of

the response to irradiation of A2B2O7 pyrochlores. Molecular dynamics simulations

showed that the annealing of interstitials created by irradiation depended upon the

nature of B. As the coordination number of B decreased, the dumb-bell interstitial

was stabilized at the expense of the isolated interstitial. Unlike the isolated

interstitials, the recombination of the dumb-bells was thermally activated and

hindered at low temperatures. The occurrence of dumb-bells drove the structure

towards the amorphous state.

Key Role of the Cation Interstitial Structure in the Radiation Resistance of

Pyrochlores. A.Chartier, G.Catillon, J.P.Crocombette: Physical Review Letters,

2009, 102[15], 155503