Thumbnail
Access Restriction
Open

Author White, Michael A. ♦ Ochsenbein, Stefan T. ♦ Gamelin, Daniel R. ♦ Lovejoy, Tracy C. ♦ Olmstead, Marjorie A.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ NANOSCIENCE AND NANOTECHNOLOGY ♦ ARGON IONS ♦ BINDING ENERGY ♦ COBALT ♦ COBALT COMPOUNDS ♦ COBALT IONS ♦ CONCENTRATION RATIO ♦ CRYSTALS ♦ DECOMPOSITION ♦ DOPED MATERIALS ♦ ELECTRONIC STRUCTURE ♦ MAGNETIC MATERIALS ♦ MAGNETIC PROPERTIES ♦ NANOSTRUCTURES ♦ SPUTTERING ♦ VALENCE ♦ X-RAY PHOTOELECTRON SPECTROSCOPY ♦ ZINC OXIDES ♦ CHALCOGENIDES ♦ CHARGED PARTICLES ♦ CHEMICAL REACTIONS ♦ DIMENSIONLESS NUMBERS ♦ ELECTRON SPECTROSCOPY ♦ ELEMENTS ♦ ENERGY ♦ IONS ♦ MATERIALS ♦ METALS ♦ OXIDES ♦ OXYGEN COMPOUNDS ♦ PHOTOELECTRON SPECTROSCOPY ♦ PHYSICAL PROPERTIES ♦ SPECTROSCOPY ♦ TRANSITION ELEMENT COMPOUNDS ♦ TRANSITION ELEMENTS ♦ ZINC COMPOUNDS
Abstract Nanoscale enrichments resulting from spinodal decomposition have been proposed to contribute to the interesting magnetic properties of diluted magnetic oxides such as cobalt-doped ZnO (Zn{sub 1-x}Co{sub x}O), but little is known experimentally about the electronic structures or physical properties of such enrichments. Here, x-ray photoelectron spectroscopy (XPS) is used to examine wurtzite Zn{sub 1-x}Co{sub x}O crystallites over the full composition range (0.0{<=}x{<=}1.0) that serve as models of the proposed spinodal decomposition nanostructures within Zn{sub 1-x}Co{sub x}O bulk materials. With increasing x, the valence band edge shifts to smaller binding energies and the cobalt 2p peaks shift to greater binding energies, providing spectroscopic signatures that may allow identification of spinodal decomposition in bulk Zn{sub 1-x}Co{sub x}O. Reduction of Co{sup 2+} to Co{sup 0} by argon ion (Ar{sup +}) sputtering was also found to become markedly more facile with increasing x, suggesting that locally-enriched Zn{sub 1-x}Co{sub x}O is at greater risk of yielding false-positive Co{sup 0} XPS signals than uniformly dilute Zn{sub 1-x}Co{sub x}O with the same overall composition.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2010-05-15
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 107
Issue Number 10


Open content in new tab

   Open content in new tab