Regensburg 2004 – wissenschaftliches Programm
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M: Metallphysik
M 12: Phasenumwandlungen II
M 12.1: Vortrag
Dienstag, 9. März 2004, 10:15–10:30, H16
Screening effects in the binary alloy systems Cu-Au, Cu-Pd, and Au-Ni — •H. Reichert, A. Schöps, I. Ramsteiner und H. Dosch — MPI für Metallforschung, Heisenbergstr. 3, D-70569 Stuttgart
Electronic screening effects are one of the origins of long-range interactions in many binary metallic alloys. Experimentally this can be studied via the singularities in the response functions at specific points in reciprocal space (Kohn anomalies, 2kF Fermi surface nesting). These singularities are the origin of a marked fine structure of the diffuse scattering in binary systems. We have investigated the fine structure of the diffuse scattering in-situ as a function of temperature in various binary alloy systems (Cu-Au, Cu-Pd, Au-Ni) using high energy x-ray scattering. In the diffuse scattering maps we found unique signatures of electronic screening in all systems. The corresponding nesting constructions are immediately apparent from the scattering data. The data sets we present are a test bench for electronic structure calculations.