Integrating near-edge X-ray absorption fine structure (NEXAFS) microscopy and crystallography:: the effects of molecular order

The carbon K-edge near-edge X-ray absorption spectra (NEXAFS) of oriented single crystals of N,N"-ethylenebis(N'-2-methylphenyl)-urea have been recorded using scanning transmission X-ray microscopy (STXM). The single-crystal structure has been determined by X-ray crystallography. A strong polarization dependence (linear dichroism) has been observed and interpreted with the aid of the single-crystal structure and crystal alignment. These results demonstrate the ability of STXM to determine molecular orientation on a submicrometre spatial scale.