An attempt to correlate ion irradiation behaviour and chemical durability of titanate- and zirconate-based ceramics

摘要

Titanate and zirconate samples from perovskite and pyrochlore families have been submitted to low energy heavy ion irradiation in order to pre-damage their crystalline structure. Samples irradiated below or near their amorphisation threshold were then leached in deionised water at 90 ℃ in static mode while samples irradiated above their amorphisation threshold were leached at 100 ℃ in dynamic mode. Below the amorphisation threshold, only slight effects of the pre-irradiation have been found on the chemical durability of titanate and zirconate from the perovskite family. Above the amorphisation threshold, perovskite surfaces exhibit a stronger hydration and an increase of the growth kinetics of secondary phases identified as TiOOH and ZrOOH compounds mainly. The pre-irradiated pyrochlore (Nd_2Zr_2O_7) exhibits both a higher hydration degree and a higher Nd-Zr surface co-enrichment due to the destabilization of their network by the pre-irradiation.