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Title: Growth of praseodymium oxide on Si(111) under oxygen-deficient conditions

Surface science studies of thin praseodymium oxide films grown on silicon substrates are of high interest in view of applications in such different fields as microelectronics and heterogeneous catalysis. In particular, a detailed characterization of the growth and the final structure of the films are mandatory to achieve a fundamental understanding of such topics as oxygen mobility and defect structure, and their role for the electronic and chemical properties. In this paper, the MBE growth of praseodymium oxide films on Si(111) substrates was investigated at low-deposition rates (0.06 nm/min) and low-oxygen partial pressures (p(O{sub 2})<1x10{sup -10} mbar). To obtain insight into the structure and chemical composition of the growing film, spot profile analyzing low-energy electron diffraction (SPA-LEED), transmission electron microscopy, and synchrotron radiation-based x-ray photoelectron spectroscopy (XPS) and x-ray absorption spectroscopy (XAS) were applied. SPA-LEED reveals the formation of an initial closed layer followed by continuous roughening and formation of ordered three-dimensional structures. This result is in contrast to observations at higher-deposition rates, were a layer-by-layer growth was reported. XAS and XPS provide evidence that a continuous reaction takes place in the growing Pr{sub 2}O{sub 3} film leading to the formation of silicate and silicide structures within the film. Combiningmore » all data, a consistent picture of the deposition of praseodymium oxide on Si(111) emerges which clearly shows that in contrast to higher-throughput molecular beam epitaxy conditions the reactivity of the growing film strongly influences the growth behavior at low-deposition rates and low pressures.« less
Authors:
 [1] ;  [2] ; ;  [1] ; ; ; ; ;  [3] ;  [4] ; ;  [5] ;  [6] ;  [7]
  1. Institute of Applied and Physical Chemistry, University of Bremen, Leobener Str. NW2, D-28359 Bremen (Germany)
  2. (Germany)
  3. Institute of Solid State Physics, University of Bremen, P.O. Box 330440, D-28334 Bremen (Germany)
  4. Department of Physics and Materials Science, Uppsala University, P.O. Box 530, SE-75121 Uppsala (Sweden)
  5. IHP, Im Technologiepark 25, D-15236 Frankfurt/ Oder (Germany)
  6. Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway)
  7. Department of Physics, University of Osnabrueck, Barbarastrasse 7, D-49069 Osnabrueck (Germany)
Publication Date:
OSTI Identifier:
21287049
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 80; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevB.80.045414; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION SPECTROSCOPY; CHEMICAL COMPOSITION; CHEMICAL PROPERTIES; CRYSTAL GROWTH; DEPOSITION; ELECTRON DIFFRACTION; HETEROGENEOUS CATALYSIS; LAYERS; MOBILITY; MOLECULAR BEAM EPITAXY; OXYGEN; PRASEODYMIUM OXIDES; REACTIVITY; SILICON; SUBSTRATES; SURFACES; SYNCHROTRON RADIATION; THIN FILMS; THREE-DIMENSIONAL CALCULATIONS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY PHOTOELECTRON SPECTROSCOPY; X-RAY SPECTRA; X-RAY SPECTROSCOPY