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 2 0 to 900 K. The dose required for amorphization was monitored by selec ted-area electron diffraction. All of the compounds were found to beco me amorphous over the temperature range investigated, although a signi ficant variation was observed in the critical amorphization temperatur e, i.e., the temperature above which amorphization was not induced. Th is variation is related to chemical differences through a combination of factors, including bonding variations and the ratio of electronic-t o-nuclear energy loss. Some of the perovskite-structure compounds unde rgo one or more instantaneous displacive phase transitions; however, t hese structural changes were not found to significantly affect the amo rphization dose in these experiments. (C) 1998 Published by Elsevier S cience B.V. All rights reserved.