PNNL

Abstract

Defect formation induced by erbium implantation in silica glass and cristobalite was studied using molecular dynamics simulations employing a partial charge model in combination with the ZBL potential. The results show that the number of displaced atoms generated at the same PKA energy is similar in silica and cristobalite but the number of coordination defects created is much lower in the cristobalite than in silica glass. In both cases, the erbium ion is able to create an optimal coordination environment at the end of the collision cascade. Subsequent thermal annealing causes the relaxation of the silicon oxygen network structure along with a reduction of silicon and oxygen defects. This research is supported by the Divisions of Materials Sciences and Engineering and Chemical Science, Office of Basic Energy Sciences, U.S. Department of Energy. The Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.