Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Measurement of c-axis angular orientation in calcite (CaCO 3 ) nanocrystals using X-ray absorption spectroscopy

P. U. P. A. Gilbert, Anthony Young and Susan N. Coppersmith
Proceedings of the National Academy of Sciences of the United States of America
Vol. 108, No. 28 (July 12, 2011), pp. 11350-11355
Stable URL: http://www.jstor.org/stable/27978803
Page Count: 6
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Measurement of c-axis angular orientation in calcite (CaCO
          3
          ) nanocrystals using X-ray absorption spectroscopy
Preview not available

Abstract

We demonstrate that the ability to manipulate the polarization of synchrotron radiation can be exploited to enhance the capabilities of X-ray absorption near-edge structure (XANES) spectroscopy, to include linear dichroism effects. By acquiring spectra at the same photon energies but different polarizations, and using a photoelectron emission spectromicroscope (PEEM), one can quantitatively determine the angular orientation of micro- and nanocrystals with a spatial resolution down to 10 nm. XANES-PEEM instruments are already present at most synchrotrons, hence these methods are readily available. The methods are demonstrated here on geologic calcite (CaCO3) and used to investigate the prismatic layer of a mollusk shell, Pinctada fucata. These XANES-PEEM data reveal multiply oriented nanocrystals within calcite prisms, previously thought to be monocrystalline. The subdivision into multiply oriented nanocrystals, spread by more than 50°, may explain the excellent mechanical properties of the prismatic layer, known for decades but never explained.

Page Thumbnails

  • Thumbnail: Page 
11350
    11350
  • Thumbnail: Page 
11351
    11351
  • Thumbnail: Page 
11352
    11352
  • Thumbnail: Page 
11353
    11353
  • Thumbnail: Page 
11354
    11354
  • Thumbnail: Page 
11355
    11355