Dramatic change of the kinetics of the phase transition induced in pure zirconia by swift heavy-ion irradiation

Abstract

It is generally admitted that the irradiation of crystallinematerials with high-energy heavy ions often leads to theformation of highly defective or amorphous tracks. In the lattercase, the amorphization process follows a single-ion-impactmechanism. However, recent results demonstrate that in certaincircumstances crystalline-to-crystalline phase transitions canalso occur. This is well illustrated with the case of purezirconia which can undergo a transition from the monoclinic to thetetragonal phase with a kinetics characterized by a sigmoidalshape. The present study provides new evidence that thistransformation is driven by a double-ion-impact mechanism.Another important finding is that the steepness of the sigmoiddepends drastically on the amount of the electronic-energy loss: asmall change in this parameter leads to a catastrophicmodification of the kinetics of the phase transition.