Thermal spike recrystallisation: Molecular dynamics simulation of radiation damage in polymorphs of titania

Molecular dynamics simulations are used to study amorphisation resistance in the rutile, brookite and anatase polymorphs of titania. As an alternative to the traditional large-scale cascade calculation, small thermal spike simulations are used to quantify recrystallisation on the picosecond scale. In agreement with experiment, the thermal spikes in rutile recover completely (within 5 ps), remain largely intact in anatase, while brookite exhibits intermediate behaviour. Analysis of the annealing response shows that the thermal spike approach captures much of the cascade physics at a fraction of the computational cost, and in doing so provide insight into the radiation response process.