Lattice dynamics of systems with two interfaces

Abstract
The composite materials with two interfaces studied here are formed out of one slab sandwiched between two other semi-infinite crystals. The corresponding response function is obtained in closed form for a simple phonon model of simple cubic crystals. Knowledge of this function enables the authors to study all the vibrational properties of such a system. An application is given here for the sandwich phonons (localised phonons within the slab).