Topological signatures and stability of hexagonal close packing and Barlow stackings. Issue 40 (27th September 2021)

• Record Type: Journal Article
• Authors: Osang, Georg; Edelsbrunner, Herbert; Saadatfar, Mohammad
• Is Part Of: Soft matter. Volume 17:Issue 40(2021)
• Page Start: 9107
• Page End: 9115
• Publication Date: 2021-09-27
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/d1sm00774b
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : 3D rendering of the experimental packing obtained via X-ray CT. A cut-out section shows the bulk crystallisation and partially crystallised regions. Abstract : Two common representations of close packings of identical spheres consisting of hexagonal layers, called Barlow stackings, appear abundantly in minerals and metals. These motifs, however, occupy an identical portion of space and bear identical first-order topological signatures as measured by persistent homology. Here we present a novel method based on k -fold covers that unambiguously distinguishes between these patterns. Moreover, our approach provides topological evidence that the FCC motif is the more stable of the two in the context of evolving experimental sphere packings during the transition from disordered to an ordered state. We conclude that our approach can be generalised to distinguish between various Barlow stackings manifested in minerals and metals.