Structure and Properties of Strained Crystalline Multilayers
We present a computer simulation study of thin crystalline multilayers constructed from two FCC solids with differing lattice constants and binding energies. Both materials are described by Lennard-Jones interatomic potentials and initially have the same orientation and coherent interfaces. We have studied systems in which interfaces are perpendicular to the common [100] and [111] directions, respectively. A novel technique for analyzing local atomic ordering, Common Neighbor Analysis, is used to identify structural characteristics in these systems. We have found several structural changes in the layers of smaller atoms, including an FCC to HCP transition. In a system with (111) texture, a coherent interface to incoherent interface transformation is observed. Calculations of elastic constants of these multilayer structures show that elastic anomalies are associated with the structural variations.
The effect of compressibility on the stability of plasma jets with boundaries (tangential discontinuity surfaces) of different configurations is studied. It is shown that, depending on the relationship between the MHD parameters of the jet and the surrounding medium, the compressibility may have a stabilizing or a destabilizing effect. It is also shown that, under certain conditions, the compressibility effect depends on the perturbation wavelength.