Dresden 2011 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
MM: Fachverband Metall- und Materialphysik
MM 23: Phase Transformations I
MM 23.7: Talk
Wednesday, March 16, 2011, 12:30–12:45, IFW D
Ground state structure in Au-50 at.% Pd — •Cédric Sax1, Bernd Schönfeld1, and Andrei Ruban2 — 1LMPT, Department of Materials, ETH Zurich — 2KTH Stockholm, Sweden
From experiment no ordered structure is known for the bulk Au-Pd system. Electronic structure calculations indicate the CH structure for 1:1 stoichiometry, diffuse scattering also allows plausible candidates for ordered structures to be discussed. In this work diffuse x-ray scattering was measured at room temperature from a single crystal of Au-48 at.% Pd. The crystal was aged at 703 K to set up a state of thermal equilibrium. The short-range order scattering is characterized by 2kF maxima where kF is the Fermi wave vector along <110>. From the separated short-range order scattering effective pair interaction parameters were determined. Ordering energies were calculated for several L10-based long-period superstructures (LPS) as LPS are favorably formed in systems with 2kF maxima. These results from diffuse scattering will be compared with those from recent electronic structure calculations.