An algorithm for Bragg coherent x-ray diffractive imaging of highly strained nanocrystals. (20th January 2020)

• Record Type: Journal Article
• Authors: Wang, Ziyi; Gorobtsov, Oleg; Singer, Andrej
• Is Part Of: New journal of physics. Volume 22:Number 1(2020:Jan.)
• Publication Date: 2020-01-20
• Subjects: x-ray imaging -- coherent diffractive imaging -- phase transformation -- phase morphology -- phase retrieval; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/ab61db
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: By using phase retrieval, Bragg coherent diffractive imaging (BCDI) allows tracking of three-dimensional displacement fields inside individual nanocrystals. Nevertheless, during structural phase transformations, significant strains (1% and higher) are common, and BCDI fails due to the Bragg peak distortions. Here we present and advanced BCDI algorithm enabling imaging three-dimensional strain fields in highly strained crystals with separated structural phases. We test the algorithm on particles simulated to undergo a structural phase transformation. While the conventional algorithms fail in unambiguously reconstructing the phase morphology, our algorithm correctly retrieves the morphology of coexistent phases with a strain difference of 1%. The key novelty is the simultaneous reconstruction of multiple scans of the same nanoparticle at snapshots through the phase transformations. The algorithm enables visualizing phase transformations in nanoparticles of lithium-ion, sodium-ion nanoparticles, and other nanoparticulate materials in working conditions (operando).