Molecular Dynamics Simulation of Overlapping Swift Heavy Ion
Impacts in Lu2O3
Kenneth Sanders
Department of Nuclear Engineering, University of Tennessee
Rare earth lanthanide sesquioxides (A2O3) are a class of simple oxides that exhibit a wide range of polymorphism under various conditions. Sesquioxides are used for several optical applications, including gain media for lasers, and these compounds are stable such that most rare earth elements can form one or another of the sesquioxide crystal structures. This last fact makes possible systematic studies on the effect of cation size on various physical properties, or on structural responses to far-from-equilibrium conditions. Swift heavy ion (SHI) irradiation, where a heavy, high energy ion impinges on a material, is one method of producing extreme local disorder in materials. Energy is deposited into the material mainly via ion-electron interactions, which frequently produces a disordered, cylindrical region, called an ion track. Building on Project 1, the purpose of these simulations were to examine how two overlapping tracks from SHI irradiation interact with each other in a 18x18x10 cell of Lu2O3 (Ia-3). Since classical Molecular Dynamics does not directly handle electronic motion, the structural evolution of the system was initiated by giving atoms within a cylinder of radius 30 Å high velocities corresponding to 5 eV/atom (~38,000 K). As in the previous Project, interatomic potential had a hybrid Buckingham-ZBL form. High energy densities produce complex atomic movement between the tracks, where defect annealing and atomic diffusion are simultaneously active, as well as atomic mixing at the track/crystal interface. Radial distribution functions confirmed two distinct structures in the track and track overlap regions. The visualization below is a cutout of the larger cell showing a cross-section of a cylinder of excited atoms corresponding to an ion track (center) next to a quenched disordered track (bottom left).
Interactive Structure
Color Legend:
- Green = Lu3+
- Red = O2-
posted: May 2026.
updated: May 2026.