[SY-B3] Symposium B-3

[SY-B3] Mobility of small vacancy and interstitial prismatic dislocation loops in BCC tungsten

^○Jan Fikar¹, Roman Gröger¹, Robin Schäublin² (1.Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Brno, Czech Republic, Switzerland, 2.Laboratory of Metal Physics and Technology, Department of Materials, ETH Zürich, Switzerland)

Vacancies and self interstitials produced in collision cascades often form clusters, which can further collapse into prismatic dislocation loops. In BCC metals dislocation loops with Burgers vectors 1/2<111> and <100> are observed and they can be either vacancy or interstitial type. These dislocation loops usually move easily in the direction of the Burgers vector. The mobility of prismatic dislocation loops is studied by molecular dynamics. The small dislocation loops under 100 defects seem to behave more like point defect clusters and the mobility of vacancy loops is substantially lower than the one of interstitial loops. Similar effect is observed in formation energies, where the small vacancy loops have higher formation energies than the corresponding interstitial loops. At larger sizes the dislocation loops seem to behave as perfect dislocations and there is no difference between vacancy and interstitials loops mobilities and formation energies.