The role of thermal spikes in energetic displacement cascades has been investigated by molecular-dynamics computer simulation. For cascade energies of 3 and 5 keV in Cu, which are the highest energies (in reduced units) yet treated by fully dynamical simulations, it is found that local melting occurs and persists for several picoseconds. The implications of this behavior for atomic mixing, Frenkel-pair production, and point-defect clustering are discussed.

• Received 2 June 1987

DOI:https://doi.org/10.1103/PhysRevLett.59.1930