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Title: Alloying and oxidation of in situ produced core-shell Al@Yb nanoalloy particles—An “on-the-fly” study

Core-shell-structured nanoalloy particles with an Al-dominated interior covered by few Yb monolayers have been fabricated using a vapor-aggregation method involving magnetron sputtering. The radially segregated structure of the Yb-Al nanoparticles has been disclosed by “on-the-fly” photoelectron spectroscopy monitoring of the nanoparticle beam in Yb 4f and Al 2p electron binding energy regions. Both, the binding energy values and the electron microscopy images taken on the deposited nanoparticles, allow estimating their dimensions to be in the 5–10 nm range. The photoelectron spectroscopy results suggest that in these nanoparticles no trivalent Yb – the typical case for the macroscopic Yb-Al alloy – is present. The oxidation of preformed Yb-Al nanoparticles was successfully attempted, leading to the appearance of divalent Yb surface oxide – in contrast to the bulk macroscopic Yb which is trivalent in the oxide. Our results suggest that at intermediate oxygen exposures “sandwich-like” nanoparticles of YbO/Yb/Al were synthesized. At higher O{sub 2} exposures, the oxygen seems to penetrate all the way to the Yb-Al interface. The results of the present study have to be considered when photonic applications of Yb-doped garnet nanoparticles are planned.
Authors:
 [1] ;  [2] ; ;  [3] ; ;  [4] ;  [5] ; ;  [1]
  1. College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)
  2. (Sweden)
  3. Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala (Sweden)
  4. MAX-lab, Lund University, Box 118, 22100 Lund (Sweden)
  5. Devision of Synchrotron Radiation Research, Department of Physics, Lund University, Box 118, 22100 Lund (Sweden)
Publication Date:
OSTI Identifier:
22419825
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALLOYS; BINDING ENERGY; DEPOSITS; DOPED MATERIALS; ELECTRON MICROSCOPY; ELECTRONS; MAGNETRONS; MONITORING; NANOPARTICLES; OXIDATION; OXIDES; OXYGEN; PHOTOELECTRON SPECTROSCOPY; SPUTTERING