title: Breakdown of the dipole approximation in core losses.
abstract: The validity of the dipole approximations commonly used in the inelastic scattering theory for transmission electron microscopy is reviewed. Both experimental and numerical arguments are presented, emphasizing that the dipole approximations cause significant errors of the order of up to 25% even at small momentum transfer. This behavior is attributed mainly to non-linear contributions to the dynamic form factor due to the overlap of wave functions.
authors: Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria. stefan.loeffler@tuwien.ac.at
authors: S
authors: S
authors: Löffler
authors: I
authors: I
authors: Ennen
authors: F
authors: F
authors: Tian
authors: P
authors: P
authors: Schattschneider
authors: N
authors: N
authors: Jaouen