PHYS 87 |
| The determination of crystallographic orientation and domains of individual nanostructures presents a general challenge in nanospectroscopy and –imaging. Tip-scattering and –enhanced Raman spectroscopy has proven to be a powerful tool for imaging with ultrahigh spatial resolution and sensitivity. Here we show that by taking advantage of the selection rules of the Raman response in combination with the polarization selective field enhancement of the probe tip allows for probing local crystallographic orientation. Varying optical polarization and angle of k-vector of incident and scattered Raman light with respect to the tip axis, together with the azimuthal sample orientation, selective Raman active phonon modes are probed. From the symmetry of the Raman tensor together with the space group of the nanocrystal the crystallographic axis can then be determined and crystal domains identified with spatial resolution down to 10 nm. Here, we demonstrate the application to nanocrystalline materials including BaTiO3, ZnO, BiFeO3, and VO2. |
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Spectroscopy, Chemistry, and Imaging through Nanophotonics
1:20 PM-5:20 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 340/341, Oral
Division of Physical Chemistry |