Optical spectroscopy and X-ray diffraction were used to study the behavior of polycrystalline samples of pure monoclinic material, bombarded with low-energy ions. A microscopic model based upon these experiments was proposed to explain a displacive phase transition observed after bombardment. Defects, produced in the O sub-lattice, introduced large strain fields at the nm-scale. This strain field could be treated as a second-order parameter within the Landau theory approach, leading to a decrease in the phase transition temperature and quenching the high-temperature tetragonal phase. The model also explained the effect of annealing in restoring the ground-state monoclinic structure.

Impact of Radiation Defects on the Structural Stability of Pure Zirconia. D.Simeone, G.Baldinozzi, D.Gosset, S.LeCaër, L.Mazerolles: Physical Review B, 2004, 70[13], 134116 (7pp)