ASJC Scopus subject areas
Quantitative electron crystallography with omega energy filtering. / Spence, J. C.H.; Mayer, J.; Zuo, J. M.In: Micron and Microscopica Acta, Vol. 22, No. 1-2, 1991, p. 173-174.
Research output: Contribution to journal › Article › peer-review
TY - JOUR
T1 - Quantitative electron crystallography with omega energy filtering
AU - Spence, J. C.H.
AU - Mayer, J.
AU - Zuo, J. M.
N1 - Funding Information: to adjust the sensitivity of certain regions of the data to certain parameters. Observed deviations from Poisson statistics are under study. The accuracy obtainable in this work has been carefully analysed \[5\]a,nd is found to depend greatly on the treatment of the background due to inelastic scattering. For phase measurement in particular, where two-dimensional data sets are usually required, a parallel detection imaging energy filter is required. An Omega filter \[6\f]itted to the new Zeiss EM91 2 TEM appears to be ideal for this work, particularly if fitted with a CCD camera \[7\]L,aB6 filament and double-tilt cold stage to minimize contamination. Fig. 1 compares the (220) systematics in Si at 100 kV recorded on this machine with and without zero-loss omega energy filtering. The probe diameter is 100 nm. Since phonon scattering is not excluded by the filter, the large reduction in background must be due to the effects of combined plasmon-phonon multiple scattering \[81F.ig. 2 compares densitometer traces. The optical density D = - In ( I (x) / I (o)), proportional to electron intensity, is plotted. (1(x) is the intensity of light transmitted through the micrograph, unexposed at x = 0). A large reduction in background in the filtered pattern is clear. Integration along the bands would further improve the quality of the data for systematics analysis. The filter allows the use of much greater thicknesses for CBED, showing many more fringes which reveal new information not previously extractable because of background. At higher voltages, the ratio of total elastic to total inelastic scattering goes as the square of the electron velocity (for thicknesses of less than an absorption length) and so improves with voltage, but radiation damage limits performance. Acknowledgements J.C.H.S. acknowledges a Humbolt Senior Scientist Award. Supported by BMFT NTS 021 5/8 and NSF grant No. DMR 88-1 3879
PY - 1991
Y1 - 1991
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U2 - 10.1016/0739-6260(91)90146-Q
DO - 10.1016/0739-6260(91)90146-Q
M3 - Article
AN - SCOPUS:44949282411
VL - 22
SP - 173
EP - 174
JO - Zeitschrift fur wissenschaftliche Mikroskopie und mikroskopische Technik
JF - Zeitschrift fur wissenschaftliche Mikroskopie und mikroskopische Technik
SN - 0968-4328
IS - 1-2