Acoustic Resonances in Solids: Pressure-, Spatial- and Photo-tuning

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

The condensed matter physics project will develop a new laser light scattering technique to measure the elastic constants of materials up to mega-bar pressures achievable in a diamond anvil cell. The research is based on the detection of standing wave resonances that develop because of surface corrugation effects. The technique is particularly useful for studies of opaque materials and will be applied to key materials important in geophysics. Experiments are proposed that should provide insights into the physics of poorly understood deformation mechanisms and elastic properties associated with buried interfaces and embedded laminar structures. The frequency profile and spatial confinement of acoustic waves confined in these systems will yield new opportunities for acoustic wave device applications. In addition, the unusual mechanical properties of a new, photo-modified, state of glass that is stabilized at optimum connectivity in binary chalcogenide glasses will be investigated. Also of interest is the important interplay between mechanical stability and pronounced glass forming tendencies related to local connectivity between atoms. The project will train graduate and undergraduate students in challenging issues in contemporary solid state physics. They will gain valuable experience with modern laser spectroscopy techniques. This education will prepare them for productive careers in academia or industry. The project will support a laser spectroscopy study of the acoustic and mechanical properties of solids. The research involves the behavior of materials under extreme compression - approaching pressures at the Earth's interior. It will develop a new method to probe high-pressure behavior of materials and will yield critical parameters for theories of material structural properties. The study dealing with high frequency acoustic waves confined to buried layers should provide important information into the physics of localized excitations. The frequency profile and spatial confinement of the waves will yield new technological opportunities that will not suffer from bandwidth limitations of conventional surface wave devices. The proposed study of glasses addresses key aspects of their elastic and optical properties through creation of a new, photo-modified, state. Of interest is how the properties of this state relate to the formation of glasses and how glass properties depend on the specific local connectivity of atoms. Together with the freedom and flexibility associated with the non-crystalline nature of glasses, the unusual light-induced effects may yield results of technological value in these useful materials. This research will be conducted with the aid of graduate and undergraduate students. They will gain valuable experience through their involvement in contemporary forefront research in solid state physics and laser spectroscopy techniques. These experiences will be of great value in their further studies, or employment in industry, academia or government laboratories.