Theoretical Study of Some Dynamical Properties of Perfect and Imperfect Crystals.

摘要

The report summarizes the work carried out with the support of AFOSR grant numbers 68-1448and 68-1448A. The work performed has been in the areas of the optical and surface properties of perfect and imperfect crystals. It has resulted in theories of Raman and Brillouin scattering of light,and infrared absorption,by phonons in metal surfaces;it has yielded first principles calculations of the microscopic crystal tensors governing these effects;it has led to the discovery of new mechanisms for light scattering by elementary excitations in insulators,semiconductors,metals and superconductors;it produced the first calculations of surface vibration modes for ionic crystals and a theory of the damping of surface modes;and led to the solution of several lattice dynamical defect problems. (Author)