No abstract

It is generally admitted that the irradiation of crystalline materials with highenergy heavy ions often leads to the formation of highly defective or amorphous tracks. In the latter case, the amorphization process follows a single-ion-impact mechanism. However, recent results demonstrate that in certain circumstances crystalline-to-crystalline phase transitions can also occur. This is well illustrated with the case of pure zirconia which can undergo a transition from the monoclinic to the tetragonal phase with a kinetics characterized by a sigmoidal shape. The present study provides new evidence that this transformation is driven by a double-ion-impact mechanism. Another important finding is that the steepness of the sigmoid depends drastically on the amount of the electronic-energy loss: a small change in this parameter leads to a catastrophic modification of the kinetics of the phase transition.c EDP Sciences