Regensburg 2010 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 54: Electronic structure II
O 54.3: Vortrag
Mittwoch, 24. März 2010, 15:30–15:45, H33
Angle-resolved photoemission in the multi-keV regime: first experimental data and theory for W and GaAs — •C. Papp1,2,3, A. Gray2,3, S. Ueda4,5, J. Minar6, L. Plucinski7, C. Sakai5, H. Yoshikawa4, Y. Yamashita4, S.-L. He4, B. Balke2,3,8, K. Kobayashi4,5, C. Schneider7, J. Braun6, H. Ebert6, and C. S. Fadley2,3 — 1Physical Chemistry II, Uni Erlangen — 2Materials Science Division, LBNL — 3Physics, UC Davis — 4SPring 8 — 5National Institute for Materials Science — 6Physical Chemistry, Uni Munich — 7Solid State Physics, Juelich Research Center — 8Inorganic and Analytical Chemistry, Uni Mainz
ARPES is the technique of choice for studying the electronic structure of solids and surfaces. However, the measurements are very surface sensitive, probing only about 1 nm into the material. In order to study bulk properties, the use of highenergy photons in the multi-keV regime is suggested. ARPES in the multi-keV regime is now possible via hard x-ray undulator beamlines, together with angle-resolving spectrometers. We will present first hard x-ray ARPES experiments on a tungsten (110)and a GaAs(001) crystal at energies of up to 6 keV. Data obtained at 30 K clearly show band structure effects for both materials, as well as photoelectron diffraction effects for corelevels and more localized valence-band states. The data will be compared with the results of both free-electron final-state theory and one-step theory including matrix element effects. Methods for correcting low-temperature data for residual phonon effects will be considered. Funded by the Humboldt foundation and the DOE (DEAC02-05CH11231).