X-ray excited optical luminescence detection by scanning near-field optical microscope: a new tool for nanoscience

Rev Sci Instrum. 2008 Jan;79(1):013702. doi: 10.1063/1.2827485.

Abstract

Investigations of complex nanostructured materials used in modern technologies require special experimental techniques able to provide information on the structure and electronic properties of materials with a spatial resolution down to the nanometer scale. We tried to address these needs through the combination of x-ray absorption spectroscopy (XAS) using synchrotron radiation microbeams with scanning near-field optical microscopy (SNOM) detection of the x-ray excited optical luminescence (XEOL) signal. This new instrumentation offers the possibility to carry out a selective structural analysis of the sample surface with the subwavelength spatial resolution determined by the SNOM probe aperture. In addition, the apex of the optical fiber plays the role of a topographic probe, and chemical and topographic mappings can be simultaneously recorded. Our working XAS-SNOM prototype is based on a quartz tuning-fork head mounted on a high stability nanopositioning system; a coated optical fiber tip, operating as a probe in shear-force mode; a detection system coupled with the microscope head control system; and a dedicated software/hardware setup for synchronization of the XEOL signal detection with the synchrotron beamline acquisition system. We illustrate the possibility to obtain an element-specific contrast and to perform nano-XAS experiments by detecting the Zn K and W L(3) absorption edges in luminescent ZnO and mixed ZnWO(4)-ZnO nanostructured thin films.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Equipment Design
  • Equipment Failure Analysis
  • Luminescent Measurements / instrumentation*
  • Luminescent Measurements / methods
  • Microscopy, Scanning Probe / instrumentation*
  • Microscopy, Scanning Probe / methods
  • Nanotechnology / instrumentation*
  • Optics and Photonics / instrumentation*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spectrometry, X-Ray Emission / instrumentation*
  • Systems Integration