Three-dimensional atomic-arrangement reconstruction from an Auger-electron hologram

Current methods for reconstructing three-dimensional atomic arrangements from photoelectron holograms require data sets recorded using multiple incident photon energies. These techniques are thus difficult to apply to Auger-electron holography, since the kinetic energy of the Auger electron is element specific and independent of excitation energy. We propose a scattering pattern extraction algorithm using a maximum-entropy method for reconstructing the three-dimensional atomic arrangement from a single-energy Auger-electron hologram. The algorithm provides a clear atomic image by taking into account the scattering of the electron by nearby atoms and the non-s-wave nature of the Auger electron. We have applied the algorithm to an Auger-electron hologram of Cu(001) recorded at SPring-8's soft x-ray synchrotron radiation beamline BL25SU and succeeded in determining the positions of 102 atoms of the Cu fcc structure.