de.mpg.escidoc.pubman.appbase.FacesBean
English
 
Help Guide Disclaimer Contact us Login
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

From embedded nanoislands to thin films: Topographic and optical properties of europium oxide on MgO(001) films

MPS-Authors
http://pubman.mpdl.mpg.de/cone/persons/resource/persons22134

Stavale,  Fernando
Chemical Physics, Fritz Haber Institute, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons32647

Pascua,  Leandro
Chemical Physics, Fritz Haber Institute, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons21916

Nilius,  Niklas
Chemical Physics, Fritz Haber Institute, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons21524

Freund,  Hans-Joachim
Chemical Physics, Fritz Haber Institute, Max Planck Society;

Locator
There are no locators available
Fulltext (public)

PhysRevB.86.085448.pdf
(Publisher version), 2MB

Supplementary Material (public)
There is no public supplementary material available
Citation

Stavale, F., Pascua, L., Nilius, N., & Freund, H.-J. (2012). From embedded nanoislands to thin films: Topographic and optical properties of europium oxide on MgO(001) films. Physical Review B, 86(8): 085448. doi:10.1103/PhysRevB.86.085448.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0010-2150-B
Abstract
Combining scanning tunnelingmicroscopy and cathodoluminescence spectroscopy, we have explored different routes to produce luminescentMgOEu films on aMo(001) support. Codeposition of Eu and Mg in an O₂ ambience turned out to be unsuitable to prepare crystalline mixed oxides with distinct emission properties because of the large mismatch between the Eu and the Mg ion radius. In contrast, highly luminescent samples were obtained after annealing MgO-supported Eu particles in oxygen. The optically active species were identified as nanosized Eu₂O₃ islands embedded in the first MgO layer, while single Eu ions inside the host lattice are of minor importance. The MgOEu adsorption system exhibits a rich photon spectrum that comprises five emission bands in the wavelength region between 565 and 725 nm. They are assigned to electron transitions from the ⁵D0 excited to the ⁷FJ ground states of Eu³⁺, with the J quantum number running from 0 to 4. From the relative intensities of certain J transitions, we conclude that the respective Eu³⁺ ions occupy sites without inversion symmetry, a condition that is best fulfilled by Eu species at the perimeter of the Eu₂O₃ nanoislands.With increasing exposure, a europium-oxide film develops on top of the MgO surface, whose weak spectral signature is compatible with Eu³⁺ ions in more centrosymmetric surroundings. Our work demonstrates that relevant properties of Eu-based phosphors, being typically prepared in the form of powder samples, can be generated in thin-film systems as well, the latter being accessible to a range of surface-science techniques due to their finite conductivity.