TY  - JOUR
AU  - Lentzen, Markus
TI  - The refractive index in electron microscopy and the errors of its approximations
JO  - Ultramicroscopy
VL  - 176
SN  - 0304-3991
CY  - Amsterdam
PB  - Elsevier Science
M1  - FZJ-2018-05882
SP  - 139
PY  - 2017
AB  - In numerical calculations for electron diffraction often a simplified form of the electron-optical refractive index, linear in the electric potential, is used. In recent years improved calculation schemes have been proposed, aiming at higher accuracy by including higher-order terms of the electric potential. These schemes start from the relativistically corrected Schrödinger equation, and use a second simplified form, now for the refractive index squared, being linear in the electric potential. The second and higher-order corrections thus determined have, however, a large error, compared to those derived from the relativistically correct refractive index. The impact of the two simplifications on electron diffraction calculations is assessed through numerical comparison of the refractive index at high-angle Coulomb scattering and of cross-sections for a wide range of scattering angles, kinetic energies, and atomic numbers.
LB  - PUB:(DE-HGF)16
C6  - pmid:28011113
UR  - <Go to ISI:>//WOS:000403992200019
DO  - DOI:10.1016/j.ultramic.2016.10.001
UR  - https://juser.fz-juelich.de/record/856488
ER  -