Dynamics and stability of subsonic crowdion clusters in 2D Morse crystal

• Main Authors: Korznikova, E. A., Shepelev, I. A., Chetverikov, A. P., Dmitriev, S. V., Fomin, S. Yu, Zhou, Kun
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Article
• Language: English
• Published: 2021
• Subjects: Engineering::Mechanical engineering; Subsonic Crowdion Clusters; Molecular Dynamics
• Online Access: https://hdl.handle.net/10356/150056
• Institution: Nanyang Technological University

Recently, the concept of supersonic N-crowdions was offered. In molecular dynamics simulations, they can be excited by initial kick of N neighboring atoms located in one close-packed atomic row along this row. In the present study, in 2D Morse crystal, we apply initial kick to M neighboring atoms located in neighboring close-packed atomic rows along these rows. This way, we initiate crowdion clusters called subsonic M-crowdions. It is well known that static 1-crowdion in 2D Morse lattice is unstable; as a result, the interstitial atom leaves the close-packed atomic row and becomes immobile. However, we show that 1-crowdion moving with sufficiently large subsonic velocity remains in the close-packed atomic row. Crowdion clusters with M equal to or greater than 2 appear to be stable even at rest, with growing M transforming into prismatic dislocation loops. It is important to note that stable subsonic M-crowdions (M > 1) remain mobile and they can carry interstitial atoms over long distances.