Study of Defects Produced by Displacement Cascades in Tantalum Monocarbide

Abstract

We used the binary collision approximation code Marlowe to simulate displacement cascades in tantalum monocarbide. We investigated the damage production, the spatial configurations of the resulting defects, and the vacancy clustering. Statistics over 5000 cascades were accumulated, and primaries with kinetic energies up to 20 keV were launched from lattice sites. Elastic collisions between atoms were modeled by the universal Ziegler–Biersack–Littmark, Moliere, and Born–Mayer potentials. The Lindhard–Scharff–Schiott theory was used to account for the inelastic energy losses. Principal components analysis was utilized to evaluate the volume of the damaged zone. Analysis of the simulation results shows that no more than 40% of the displaced Ta and C atoms constitute permanent damage. The number of surviving tantalum Frenkel pairs is about twice the carbon one. The cascade volume distributions deviate from a Gaussian distribution showing high degree of dispersion. Only small vacancy clusters are observed within the investigated range of the primary energies, and 33% of the produced vacancies are considered as isolated point defects in 20 keV cascade.