Excitation and propagation of 1-crowdion in BCC niobium lattice

Abstract

Crowdion is an interstitial atom found in a close-packed row of atoms in different crystals. Thesedefects are efficient in transferring mass and energy into the crystal lattice because they are highlymobile. In recent years, it has been studied dynamics of various excitations in different types andsizes of lattices. In this article, we considered the motion of a classical 1-crowdion (a mode localizedon a single atom has supersonic velocity in a close-packed row of atoms). Niobium has been chosenas material with bcc lattice and the analysis has been carried out for different initial velocities. It isshown that an excitation of the crowdion has the threshold character and can be induced only for sufficientlylarge initial velocity. If the latter is lower than this threshold than only soliton can be formed.It is also shown that crowdions play an important role in the formation of various mobile defectsinside metals.