Diffraction at GaAs/Fe3Si core/shell nanowires: The formation of nanofacets
Abstract
GaAs/Fe3Si core/shell nanowire structures were fabricated by molecular-beam epitaxy on oxidized Si(111) substrates and investigated by synchrotron x-ray diffraction. The surfaces of the Fe3Si shells exhibit nanofacets. These facets consist of well pronounced Fe3Si{111} planes. Density functional theory reveals that the Si–terminated Fe3Si{111} surface has the lowest energy in agreement with the experimental findings. We can analyze the x-ray diffuse scattering and diffraction of the ensemble of nanowires avoiding the signal of the substrate and poly-crystalline films located between the wires. Fe3Si nanofacets cause streaks in the x-ray reciprocal space map rotated by an azimuthal angle of 30° compared with those of bare GaAs nanowires. In the corresponding TEM micrograph the facets are revealed only if the incident electron beam is oriented along [11¯0] in accordance with the x-ray results. Additional maxima in the x-ray scans indicate the onset of chemical reactions between Fe3Si shells and GaAs cores occurring at increased growth temperatures.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 01, 2016
- Source ID
- 10.1063/1.4949009
Entities
People
- Achim Trampert
- Bernd Jenichen
- J. Herfort
- M. Hanke
- M. Hilse
- S. C. Erwin
Organizations
- European Synchrotron Radiation Facility
- Office of Naval Research Global