Coupling between order parameter and compositional fluctuations in the irradiation induced monoclinic to tetragonal phase transition in pure zirconia

摘要

Zirconia, oxidation product of Zircaloy cladding elements of nuclear plants, exhibits an unusual behaviour under irradiation. Impinging ions and neutrons induce a monoclinic to tetragonal phase transition at room temperature in this solid. To understand this modification of the positions of the stability lines in such a solid under irradiation, we have studied the monoclinic to tetragonal first order phase transition versus temperature in pure micrometric and nanometric zirconia samples. From these works, it was possible to understand the behaviour of this material under irradiation pointing out the key role of defects induced irradiation on its phase diagram.