Nanoscale shock wave generation by photodissociation of impurities in solids: A molecular dynamics study

Abstract

The dynamics of shock wave generation, propagation, and decay in an Ar lattice following photodissociation of an I2 impurity are studied using molecular dynamics simulation. A two‐dimensional model is treated to allow the modeling of shock wave propagation over larger distances than easily accessible in full three‐dimensional calculations. The shock waves are created on atomic length scales by binary collisions between the nascent photofragments and adjacent lattice atoms, and propagate long distances through the crystal in a highly directed, quasi‐one‐dimensional manner. As a consequence of the I/Ar mass ratio, the I fragments undergo multiple collisions with the adjacent Ar atoms situated along the I–I bond axis, generating pulse trains of shock waves, each with a characteristic initial energy, velocity, and decay rate. The dynamics of the system are interpreted using a simple one‐dimensional hard sphere model.