Radiation damage and evolution of radiation-induced defects in Er(2)O(3) bixbyite

Collision cascade simulations were performed in the Er(2)O(3) sesquioxide. The resulting point defects observed at the end of the ballistic phase of the collision cascade were analysed and their evaluation over longer time examined using temperature accelerated dynamics and the kinetic Monte Carlo method. The result shows that the large mass difference between the Er and O atoms results in cascades with different structures where an initially energetic O atom can channel over long distances, depositing energy in smaller sub-regions, whereas denser cascades with vacancy-rich cores develop from Er primary knock-on atoms. The most mobile defect that can form is the isolated O vacancy but when this occurs as part of a larger defect cluster it becomes trapped. The energy barriers for all other defects to move are very high.