Measurement of c-axis angular orientation in calcite (CaCO3) nanocrystals using X-ray absorption spectroscopy.

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 (CaCO(3)) and used to investigate the prismatic layer of a mollusk shell, Pinctada fucata. These XANES-PEEM data reveal multiply oriented nano

SUBMITTER: Gilbert PU 

PROVIDER: S-EPMC3136314 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature