Density and structural effects in the radiation tolerance of TiO2 polymorphs

摘要: The radiation response of TiO2 has been studied using molecular dynamics. simulations are motivated by experimental observations that the three low-pressure polymorphs, rutile, brookite and anatase, exhibit vastly different tolerances to amorphization under ion-beam irradiation. To understand role structure we perform large numbers small thermal spike method. We quantify high statistical accuracy number defects created as a function temperature type, reproduce all main trends observed experimentally. evaluate hypothesis volumetric strain relative amorphous phase is an important driving force for defect recovery, in which crystalline density varied over wide range. Remarkably, differences between polymorphs disappear once difference taken into account. This finding demonstrates factor controls tolerance TiO2.