Surfaces (Jan 2021)

Analysis of Resonant Soft X-ray Reflectivity of Anisotropic Layered Materials

  • Luca Pasquali,
  • Nicola Mahne,
  • Angelo Giglia,
  • Adriano Verna,
  • Lorenzo Sponza,
  • Raffaella Capelli,
  • Matteo Bonfatti,
  • Francesco Mezzadri,
  • Emanuele Galligani,
  • Stefano Nannarone

DOI
https://doi.org/10.3390/surfaces4010004
Journal volume & issue
Vol. 4, no. 1
pp. 18 – 30

Abstract

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We present here a method for the quantitative prediction of the spectroscopic specular reflectivity line-shape in anisotropic layered media. The method is based on a 4 × 4 matrix formalism and on the simulation from the first principles (through density functional theory—DFT) of the anisotropic absorption cross-section. The approach was used to simulate the reflectivity at the oxygen K-edge of a 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) thin film on Au(111). The effect of film thickness, orientation of the molecules, and grazing incidence angle were considered. The simulation results were compared to the experiment, permitting us to derive information on the film geometry, thickness, and morphology, as well as the electronic structure.

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