[en] This progress report discusses the work done at the Materials Science Institute in the following areas: anomalous surface state decay lengths and surface electronic structure of tungsten. 2 figs

[en] This paper discusses the following topics: surface states and resonances; surface fermi surfaces; and non-adiabatic adsorbate vibrational damping

[en] Several productive runs were made on beamline U4A at NSLS. An upgrade of angle-resolved photoemission spectrometer was largely completed on the beamline. Progress was made on studies of surface states and reconstruction on Mo(001) and W(001), and of surface states and resonances on Pt(111)

[en] A year and a half ago, we terminated our operations at the National Synchrotron Light Source and moved our research program to the Advanced Light Source in Berkeley. This move was motivated primarily by the exciting possibilities and research directions made possible by operation at the newer ALS facility. The ALS facility was commissioned in October 1993. We are members of a 'Participating Research Team' (PRT) associated with undulator beamline 7.0 at the ALS. This beamline was commissioned for experiments the following winter and spring of 1994. We have thus had about a year to debug the beamline and to try to get some experiments accomplished. Reportedly due to insufficient operating funds, the facility provided beam to users only nine 8-hour shifts per week. In the past year, our program has been devoted primarily to becoming operational at the ALS and to assembling experiments and experimental equipment associated with our program there

[en] One technique, photoelectron diffraction (PhD) is characterized. It has some promise in surmounting some of the problems of LEED. In PhD, the differential (angle-resolved) photoemission cross-section of a core level localized on an adsorbate atom is measured as a function of some final state parameter. The photoemission final state consists of two components, one of which propagates directly to the detector and another which scatters off the surface and then propagates to the detector. These are added coherently, and interference between the two manifests itself as cross-section oscillations which are sensitive to the local structure around the absorbing atom. We have shown that PhD deals effectively with two- and probably also three-dimensionally disordered systems. Its non-damaging and localized, atom-specific nature gives PhD a good deal of promise in dealing with molecular overlayer systems. It is concluded that while PhD will never replace LEED, it may provide useful, complementary and possibly also more accurate surface structural information

[en] This report discusses: surface states and resonances on Ta(011); surface states and phonon anomalies on Pt(111); and surfaces fermi contours and charge transfer

[en] This paper discusses the following topics: linewidths of surface states and resonances; surface bonds and fermi surface of Pd(001); state-resonance transition of Ta(011); and electronic structure of W(010)-2H. 5 figs

[en] This report discusses the following research topics: W(011) and Mo(011); reconstruction and relativity; Fermi surfaces and electronic susceptibilities; and surface resonances. 36 refs., 7 figs

[en] Recently, we reported high resolution angle-resolved photoemission measurements that indicated unusually strong coupling between adsorbate vibrations and a surface-localized electron state in the system W(110)-(1x1)H. We have now extended these measurements to probe the electron-phonon coupling strength as a function of position on the relevant Fermi contour. We find that the strength of the coupling is strongly dependent on Fermi wave vector, with the electron-phonon coupling constant λ varying between zero and ∼0.8. Qualitatively, the strength of the coupling is related to the position of the surface band in the projected bulk band gap, and therefore to the degree of surface localization of the surface state wave function. Such effects should play an important role in all adsorbate vibronic interactions, since the vibrational modes are generally highly localized to the outermost surface layer. We discuss these results in relation to the surface phonon anomalies observed on this surface

[en] The 3-year activity report covers surface structure and phonon anomalies (surface reconstruction on W(001) and Mo(001), adsorbate lateral ordering, surface Fermi contours and phonon anomalies on Pt(111) and Pd(001)), adsorbate vibrational damping, charge transfer in momentum space: W(011)-K, surface states and resonances (relativistic effects ampersand computations, surface resonances)