Suppressing Geometric Phase Shift Owing to Antiphase Boundaries in Dark-Field Electron Holography

Abstract

Antiphase boundaries (APBs) formed in Fe₇₀Al₃₀ alloy have attracted significant attention because they intensify ferromagnetic spin order by atomic disordering. Electron holography can be a useful tool for examining the magnetism in APB regions, although the observations suffer from an undesired contribution from an additional geometric phase shift in the incident electron wave. This paper proposes a method based on dark-field electron holography to suppress the unwanted geometric phase shift owing to APBs in electron holograms. The results of this study yield useful information for examining APBs and other planar defects in ordered crystals.

Fig. 5 Electron holograms and reconstructed phase images obtained from the rectangular region (object region) shown in Figs. 4(a)–4(b). (a)–(c) Electron holograms acquired by using 000, 100, and 200 spots, respectively. (d)–(f) Reconstructed phase images obtained from the holograms shown in (a)–(c), respectively.