Chemical bonding in phase-change chalcogenides.

J Phys Condens Matter

Peter-Grünberg-Institut PGI-1, Forschungszentrum Jülich, D-52425 Jülich, Germany.

Published: May 2024

Almost all phase-change memory materials (PCM) contain chalcogen atoms, and their chemical bonds have been denoted both as 'electron-deficient' [sometimes referred to as 'metavalent'] and 'electron-rich' ['hypervalent', multicentre]. The latter involve lone-pair electrons. We have performed calculations that can discriminate unambiguously between these two classes of bond and have shown that PCM have electron-rich, 3c-4e ('hypervalent') bonds. Plots of charge transferred between () and shared with () neighbouring atoms cannot on their own distinguish between 'metavalent' and 'hypervalent' bonds, both of which involve single-electron bonds. PCM do not exhibit 'metavalent' bonding and are not electron-deficient; the bonding is electron-rich of the 'hypervalent' or multicentre type.

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http://dx.doi.org/10.1088/1361-648X/ad46d6DOI Listing

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