zeroloss/deflection maps

Outside of microscopy the relationship between energy lost, and momentum transferred, is a subject that has found considerable application in the past 2000 years. Only recently has it become possible for electron microscopes to routinely deliver quantitative information on energy lost as well as momentum transferred.One simple and robust way to put this type of information to use is to group image-pixels according to the fraction of detected electrons removed from the zero-loss peak, versus the fraction of incident electrons scattered outside the objective aperture. These plots show promise as a robust tool for quantitative analysis of intensities in transmission electron microscopes able to form energy-filtered images.

In effect, for example, one might come close to being able to "weigh" the amount of specimen associated with each pixel in an electron microscope image field. The number of ways that this information might relate to macroscopic properties of the object under investigation is quite large. 

For instance, the figure at right uses an all-exponential scattering model for core/rim regions in microtomed slices of two separate unlayered-graphene core/rim red-giant starsmoke particles, whose isotopes suggest an asymptotic giant-branch nucleosynthesis prior to formation of the 4.5 billion-year old Murchison meteorite (and solar system) in which it was found. The inelastic-mean-free-path ratio between core and graphite rim in both particles points to a core density closer to that of liquid carbon than of graphite, suggesting formation by dendritic-solidification of a super-cooled carbon droplet prior to graphite coating in that red giant star's atmosphere.

Some related references:

• 1. R. F. Egerton (1996 2nd ed) Electron energy-loss spectroscopy in the electron microscope (Plenum Press, NY) preview.

1. Eric Mandell, "Electron Beam Characterization of Carbon Nanostructures" (2007) Ph.D. Dissertation at UM-St Louis/Rolla (link)

   1. P. Fraundorf, K. Pisane, E. Mandell, R. Collins (2010) "Zero-loss/deflection map analysis" Microscopy and MicroAnalysis 16 Supplement 2, 1534-1535 arXiv:1203.6342.