Electronic and spectroscopic properties of early 3d metal atoms on a graphite surface

• Published in: Surface science 1995-07, Vol.331-333, p.741-745
• Main Authors: Rakotomahevitra, A., Garreau, G., Demangeat, C., Parlebas, J.C.
• Format: Article
• Language: English
• Subjects: Adatoms; Chemisorption; Chromium; Clean metal, semiconductor, and insulator surfaces; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron and ion emission by liquids and solids; impact phenomena; Electron density, excitation spectra calculations; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Graphite; Magnetic phenomena; Many body and quasi-particle theories; Photoelectron emission; Photoemission and photoelectron spectra; Physics; Semi-empirical models and model calculations; Surface and interface electron states; Surface defects; Surface states, band structure, electron density of states; Vanadium; X-ray photoelectron spectroscopy
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(95)00210-3

High-sensitivity magneto-optic Kerr effect experiments failed to detect manifestations of magnetism in epitaxial films of V on Ag(100) substrates. More recently V 3s XPS of freshly evaporated V clusters on graphite exhibited the appearance of a satellite structure which has then been interpreted by the effect of surface magnetic moments on V. It is the absence of unambiguous results on the electronic properties of early 3d supported metals that prompts us to examine the problem. Our purpose is twofold. In a first part, after a total energy calculation within a tight-binding method which yields the equilibrium position of a given adatom, we use the Hartree-Fock approximation to find out a possible magnetic solution of V (or Cr) upon graphite for a reasonable value of the exchange integral Jdd. In a second part the informations given by the density of states of the graphite surface as well as the additional states of the adsorbed atom are taken into account through a generalised impurity Anderson Hamiltonian which incorporates the various Coulomb and exchange interactions necessary to analyse the 3s XPS results.