Three-Dimensional Imaging of Phase Ordering in an Fe-Al Alloy by Bragg Ptychography

Chan Kim (1) , Virginie Chamard (2) , Jörg Hallmann (1) , Thomas Roth (1) , Wei Lu (1) , Ulrike Boesenberg (1) , Alexey Zozulya (1) , Steven Leake (3) , Anders Madsen (1)

1 XFEL - European XFEL GmbH
2 COMiX - Coherent Optical Microscopy and X-rays
3 ESRF - European Synchrotron Radiation Facility

We show three-dimensional images of phase ordering in a Fe 55 Al 45 alloy obtained by coherent x-ray diffraction Bragg ptychography. Fe-Al alloys display ordered phases where the atoms organize on sublattices resulting in the emergence of otherwise forbidden superlattice reflections. The degeneracy of the ordering results in antiphase domain boundaries that, in addition to the general lattice strain, provide phase shifts of the diffracted beam depending on the reflection. The reconstructed phase images can be separated into components originating from B2 phase domains and lattice strain by performing Bragg ptychography on both the (002) fundamental and the (001) superlattice reflections.

Keywords: Three-Dimensional Graphics; Bragg ptychography; Fe; X ray diffraction; Intermetallic alloy

Domains: Physics [physics]; Condensed Matter [cond-mat]

Chan Kim, Virginie Chamard, Jörg Hallmann, Thomas Roth, Wei Lu, et al.. Three-Dimensional Imaging of Phase Ordering in an Fe-Al Alloy by Bragg Ptychography. Physical Review Letters, 2018, 121 (25), pp.256101. ⟨10.1103/physrevlett.121.256101⟩. ⟨hal-01975963⟩