NANOSCALE SHOCK-WAVE GENERATION BY PHOTODISSOCIATION OF IMPURITIES IN SOLIDS - A MOLECULAR-DYNAMICS STUDY

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. © 1995 American Institute of Physics.