On the origin of diffuse intensities in fcc electron diffraction patterns.

Autor: Coury FG; Materials Engineering Department (DEMa), Universidade Federal de São Carlos, São Carlos, Brazil. fgcoury@ufscar.br., Miller C; SIGMA Division, Los Alamos National Laboratory, Los Alamos, NM, USA., Field R; Colorado School of Mines, Golden, CO, USA., Kaufman M; Colorado School of Mines, Golden, CO, USA. mkaufman@mines.edu.
Jazyk: angličtina
Zdroj: Nature [Nature] 2023 Oct; Vol. 622 (7984), pp. 742-747. Date of Electronic Publication: 2023 Oct 25.
DOI: 10.1038/s41586-023-06530-6
Abstrakt: Interpreting diffuse intensities in electron diffraction patterns can be challenging in samples with high atomic-level complexity, as often is the case with multi-principal element alloys. For example, diffuse intensities in electron diffraction patterns from simple face-centred cubic (fcc) and related alloys have been attributed to short-range order 1 , medium-range order 2 or a variety of different {111} planar defects, including thin twins 3 , thin hexagonal close-packed layers 4 , relrod spiking 5 and incomplete ABC stacking 6 . Here we demonstrate that many of these diffuse intensities, including [Formula: see text]{422} and [Formula: see text]{311} in ⟨111⟩ and ⟨112⟩ selected area diffraction patterns, respectively, are due to reflections from higher-order Laue zones. We show similar features along many different zone axes in a wide range of simple fcc materials, including CdTe, pure Ni and pure Al. Using electron diffraction theory, we explain these intensities and show that our calculated intensities of projected higher-order Laue zone reflections as a function of deviation from their Bragg conditions match well with the observed intensities, proving that these intensities are universal in these fcc materials. Finally, we provide a framework for determining the nature and location of diffuse intensities that could indicate the presence of short-range order or medium-range order.
(© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE
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