Implementation of Gold deconvolution for enhanced energy resolution in EEL spectra

• Gold’s iterative deconvolution algorithm has been applied to one-dimensional EEL spectra from hexagonal BN. The experimental resolution was varied from 1.1 to 2.25 eV and Gold’s algorithm was able to restore low-loss and core-loss spectra overall well. To estimate the instrument response function, the most convenient method was to extract the zero-loss peak from the low-loss spectrum. It was also found as suggested by Egerton, that by using low-loss spectra as kernel, enhanced energy resolution could be obtained as plural scattering was simultaneously removed. It’s further shown how the FWHM of the p* peak in the boron K‑edge of hexagonal BN is reduced from 1.4 to 0.7 eV with almost no noise-amplification after 500 iterations while resolving the s* doublet. The result was almost identical after a stunning 5 000 - 10 000 iterations, implying that Gold’s method converges and can be stable for a large number of iterations. However, for lower-intensity spectra the number of iterations is limited. The results close to the intense zero-loss peak were uncertain and further testing with better experimental resolution is recommended. It’s also found that to improve the resolution and not just sharpen the spectra, a large number of iterations is required.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

EELS

Gold deconvolution

Resolution improvement

Hexagonal boron nitride

Physics

Fysik

fysik

Physics

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