Effects of ionizing and displacive irradiation on several perovskite-structure oxides

Synthetic single crystals of CaTiO3, SrTiO3, BaTiO3, KNbO3, and KTaO3 were irradiated by 800 keV Kr+ ions over a range of temperature from 20 to 900 K. The dose required for amorphization was monitored by selected-area electron diffraction. All of the compounds were found to become amorphous over the temperature range investigated, although a significant variation was observed in the critical amorphization temperature, i.e., the temperature above which amorphization was not induced. This variation is related to chemical differences through a combination of factors, including bonding variations and the ratio of electronic-to-nuclear energy loss. Some of the perovskite-structure compounds undergo one or more instantaneous displacive phase transitions; however, these structural changes were not found to significantly affect the amorphization dose in these experiments. (C) 1998 Published by Elsevier Science B.V. All rights reserved.