Discovering Electron-Transfer-Driven Changes in Chemical Bonding in Lead Chalcogenides (PbX, where X = Te, Se, S, O)

0538069 - ÚFCH JH 2021 RIV DE eng J - Journal Article
Maier, S. - Steinberg, S. - Cheng, Y. - Schön, C. F. - Schumacher, M. - Mazzarello, R. - Golub, Pavlo - Nelson, R. - Cojocaru-Mirédin, O. - Raty, J. Y. - Wuttig, M.
Discovering Electron-Transfer-Driven Changes in Chemical Bonding in Lead Chalcogenides (PbX, where X = Te, Se, S, O).
Advanced Materials. Roč. 32, č. 49 (2020), č. článku 2005533. ISSN 0935-9648. E-ISSN 1521-4095
Institutional support: RVO:61388955
Keywords : atom probe tomography * chalcogenides * metavalent bonding * phase-change materials * thermoelectrics
OECD category: Physical chemistry
Impact factor: 30.849, year: 2020
Method of publishing: Open access

Understanding the nature of chemical bonding in solids is crucial to comprehend the physical and chemical properties of a given compound. To explore changes in chemical bonding in lead chalcogenides (PbX, where X = Te, Se, S, O), a combination of property-, bond-breaking-, and quantum-mechanical bonding descriptors are applied. The outcome of the explorations reveals an electron-transfer-driven transition from metavalent bonding in PbX (X = Te, Se, S) to iono-covalent bonding in β-PbO. Metavalent bonding is characterized by adjacent atoms being held together by sharing about a single electron (ES ≈ 1) and small electron transfer (ET). The transition from metavalent to iono-covalent bonding manifests itself in clear changes in these quantum-mechanical descriptors (ES and ET), as well as in property-based descriptors (i.e., Born effective charge (Z*), dielectric function ε(ω), effective coordination number (ECoN), and mode-specific Grüneisen parameter (γTO)), and in bond-breaking descriptors. Metavalent bonding collapses if significant charge localization occurs at the ion cores (ET) and/or in the interatomic region (ES). Predominantly changing the degree of electron transfer opens possibilities to tailor material properties such as the chemical bond (Z*) and electronic (ε∞) polarizability, optical bandgap, and optical interband transitions characterized by ε2(ω). Hence, the insights gained from this study highlight the technological relevance of the concept of metavalent bonding and its potential for materials design.
Permanent Link: http://hdl.handle.net/11104/0315892