Concentration and Strain Fields inside a Ag/Au Core–Shell Nanowire Studied by Coherent X-ray Diffraction

Sabine T. Haag (1, 2) , Marie-Ingrid Richard (1, 3) , Udo Welzel (2) , Vincent Favre-Nicolin (4) , Olivier Balmes (3) , Gunther Richter (5, 2) , Eric J. Mittemeijer (6) , Olivier Thomas (1)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2 Max-Planck-Institut für Intelligente Systeme
3 ESRF - European Synchrotron Radiation Facility
4 NRS - Nanostructures et Rayonnement Synchrotron
5 University of Stuttgart
6 Max Planck Institute for Intelligent Systems [Tübingen]

Three-dimensional coherent diffraction patterns of an isolated, single-crystalline Ag/Au core–shell nanowire were recorded at different X-ray beam energies close to the Au LIII absorption edge. Two-dimensional slices of the three-dimensional diffraction pattern, with the diffraction vector oriented perpendicular to the wire axis, were investigated in detail. In reciprocal space, facet streaks with thickness fringes were clearly observed in the two-dimensional diffraction patterns, from which the shape and size of the corresponding cross sections of the nanowire could be revealed. Comparison with simulated diffraction patterns exhibited the coherency strain field in the nanowire. During in situ annealing at temperatures which would lead to significant intermixing by volume diffusion in bulk material, according to literature data, a core–shell morphology was preserved; that is, intermixing in the nanowire was pronouncedly decelerated compared to bulk diffusion.

Domaines: Matière Condensée [cond-mat]

Sabine T. Haag, Marie-Ingrid Richard, Udo Welzel, Vincent Favre-Nicolin, Olivier Balmes, et al.. Concentration and Strain Fields inside a Ag/Au Core–Shell Nanowire Studied by Coherent X-ray Diffraction. Nano Letters, 2013, 13 (5), pp.1883--1889. ⟨10.1021/nl303206u⟩. ⟨hal-01811413⟩