They propose to study several important questions about phonons in amorphous and crystalline solids, mainly through thermal conductivity measurements. One of these questions is that of the heat flow in amorphous solids in the temperature range 10 - 300 K, with the goal of understanding the transition of the phonon picture to that of a random walk of the elastic energy. They will also continue their work on disordered crystals displaying glass-like thermal properties, in order to test several models that have been advanced as explanations. They will use these models in an attempt at identifying other disordered crystals displaying glass-like properties. Their ultimate goal is to apply their knowledge to amorphous solids, and to understand their excitations. They will also propose an investigation of phonon scattering at crystal surfaces, in order to understand and identify important scattering mechanisms. Here, their goal is to use phonons as sensitive low energy probes for surfaces.
