Elastic trapping of dislocation loops in cascades in ion-irradiated tungsten foils

Abstract

Using _in situ_ transmission electron microscopy (TEM), we have observed nanometre scale dislocation loops formed when an ultra-high-purity tungsten foil is irradiated with a very low fluence of self-ions. Analysis of the TEM images has revealed the largest loops to be predominantly of prismatic 1/2<111> type and of vacancy character. The formation of such dislocation loops is surprising since isolated loops are expected to be highly mobile, and should escape from the foil. In this work we show that the observed size and number density of loops can be explained by the fact that the loops are _not_ isolated - the loops formed in close proximity in the cascades interact with each other and with vacancy clusters, also formed in cascades, through long-range elastic fields, which prevent the escape of loops from the foil. We find that experimental observations are well reproduced by object Kinetic Monte Carlo simulations of evolution of cascades _only_ if elastic interaction between the loops is taken into account. Our analysis highlights the profound effect of elastic interaction between defects on the microstructural evolution of irradiated materials.

28 pages, 11 figures, submitted

References in corpus (3)

• High energy collision cascades in tungsten: dislocation loops structure and clustering scaling laws
• The nature of high-energy radiation damage in iron: Modeling results
• Spatial ordering of nano-dislocation loops in ion-irradiated materials

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• Relaxation volumes of microscopic and mesoscopic irradiation-induced defects in tungsten
• Displacement cascades and defects annealing in tungsten, Part II: Object kinetic Monte Carlo Simulation of Tungsten Cascade Aging
• Nanoscale lattice strains in self-ion implanted tungsten
• Distribution of defect clusters in the primary damage of ion irradiated 3C-SiC
• Atomistic-Object Kinetic Monte Carlo simulations of irradiation damage in tungsten
• Non-destructive study of collision cascade damage in self-ion irradiated tungsten using HR-EBSD and ECCI
• Reaction-drift-diffusion models from master equations: application to material defects
• 3D reconstruction of the spatial distribution of dislocation loops using a triangulation approach