This award will be used to construct a surface analytical system capable of measuring surface vibrations and phonons of materials with sub-meV energy resolution, as a function of momentum, over a temperature range from 20 Kelvins to 800 Kelvins. Simultaneous characterization of electronic and structural properties of surfaces will be possible. The fundamental properties of surface phonons for simple metals, semiconductor, insulators, and thin films will be investigated as well as the vibrational modes of surface defects and adsorbates. The improved resolution and signal will allow detailed phonon dispersion curves to be obtained for various surface structures. The surface phonon spectra will be correlated with the geometrical structure using Low Energy Electron Diffraction, Scanning Tunneling Microscopy, X-ray and Ion scattering, and with the electronic structures using XPS, AES, and Angle-resolved photoemission. Close coupling of experimental results to theoretical calculations of the lattice dynamics will be carried out. This instrument will be the first one of it's kind in the United States.
