Absence of 2kF splitting in the diffuse scattering from Cu3Au at the (001) surface

Nucleation process in Cu3Au(001) surface region around the order-disorder phase transition

The element distribution in the Cu(3)Au(001) surface region has been determined on the basis of directional Auger electron spectroscopy polar profiles measurements and interpreted in the frame of thermodynamic approach formulated for the inhomogeneous systems by using the Néel sublattices concept. Both approaches, experimental and theoretical, allowed us to present the temperature dependence of element concentration in a layer resolved mode. The wide temperature range explored in the experiment ensured the large data base for the theoretical analysis which enabled us to propose the distribution of intra-layer and inter-layer pairwise interactions leading to proper temperature dependence of segregation profiles in the surface region. This kind of interaction distribution can be understood as strain induced.

3D imaging of the Fermi surface by thermal diffuse scattering

We use thermal diffuse scattering of x rays to visualize the lens-shaped portions of the Fermi surface in metallic zinc. Our interpretation of the nature of the observed scattered intensity anomalies is supported by the incorporation of inelastic x-ray scattering measurements as well as ab initio calculations of the electronic structure and lattice dynamics. Our work demonstrates that thermal diffuse scattering complements well-established techniques and is a powerful tool in its own right for studying the shape of the Fermi surface through the associated electron-phonon coupling.

Atomic-scale surface demixing in a eutectic liquid BiSn alloy

Resonant x-ray reflectivity of the surface of the liquid phase of the Bi(43)Sn(57) eutectic alloy reveals atomic-scale demixing extending over three near-surface atomic layers. Because of the absence of an underlying atomic lattice which typically defines adsorption in crystalline alloys, studies of adsorption in liquid alloys provide unique insight on interatomic interactions at the surface. The observed composition modulation could be accounted for quantitatively by the Defay-Prigogine and Strohl-King multilayer extensions of the single-layer Gibbs model, revealing a near-surface domination of the attractive Bi-Sn interaction over the entropy.