Electron Energy Loss Spectroscopy (EELS) comes from the imaginary part of the inverse dielectric function $-\text{Im}[\varepsilon^{-1}(q, \omega)]$. If the dielectric function is actually a tensor and there is anisotropy, which component of the tensor is used to generate EELS in calculations or, alternatively, what appears in EELS experimentally?

  • $\begingroup$ Don't know very much about EELS specifically so take this with a grain of salt, but for other types of spectroscopy like optical rotation, the observed effect would be related to the trace of your tensor for a randomly oriented material. If you had an oriented sample, you could make measures along different facets to resolve each of the components of the tensor. $\endgroup$
    – Tyberius
    May 9 at 18:09
  • $\begingroup$ I gave my +1 long ago, but can you update us now that it has been 6+ months since you asked this question? Have you found the answer? Are you still actively in need of an answer? Was the comment by Tyberius helpful? $\endgroup$ Nov 5 at 15:01