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If the TEM sample is made of small particles, the particles can be dispersed in methanol and then drop and dry on a lacey C coated Cu TEM grid. EEL spectra can be obtained from the thin areas of the particles, typically <50 nm thick, overhanging holes in the lacy C film.
For EELS analysis of nanometer sized objects, contribution from the surface- and interface-related excitations may be predominant in their dielectric responses due to their large surface to volume ratio. [1] For instance, the individual nanotube can be studied by VEELS.
To obtain reliable structural data from the nano-structures (e.g. nanoparticles and nanotubes) through EELS measurements, any change in morphology must be negligible during the data acquisition. The electron beam can damage the nano-structures due to inelastic scattering in a number of ways:
i) Surface sputtering/knock-on,
ii) Bulk and surface diffusion,
iii) Possible heating of thermally isolated metallic nanoparticles.
[1] Z. L. Wang, Micron 27, 265 (1996).
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