Metavalent Bonding in Crystalline Solids: How Does It Collapse?. Issue 39 (6th August 2021)

• Record Type: Journal Article
• Authors: Guarneri, Ludovica; Jakobs, Stefan; von Hoegen, Alexander; Maier, Stefan; Xu, Ming; Zhu, Min; Wahl, Sophia; Teichrib, Christian; Zhou, Yiming; Cojocaru‐Mirédin, Oana; Raghuwanshi, Mohit; Schön, Carl‐Friedrich; Drögeler, Marc; Stampfer, Christoph; Lobo, Ricardo P. S. M.; Piarristeguy, Andrea; Pradel, Annie; Raty, Jean‐Yves; Wuttig, Matthias
• Is Part Of: Advanced materials. Volume 33:Issue 39(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-08-06
• Subjects: atom probe tomography -- bond breaking -- materials by design -- metavalent bonding -- phase‐change materials -- property maps -- thermoelectrics -- topological insulators; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202102356
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: The chemical bond is one of the most powerful, yet much debated concepts in chemistry, explaining property trends in solids. Recently, a novel type of chemical bonding was identified in several higher chalcogenides, characterized by a unique property portfolio, unconventional bond breaking, and sharing of about one electron between adjacent atoms. This metavalent bond is a fundamental type of bonding in solids, besides covalent, ionic, and metallic bonding, raising the pertinent question as to whether there is a well‐defined transition between metavalent and covalent bonds. Here, three different pseudo‐binary lines, namely, GeTe1− x Se x, Sb2 Te3(1− x ) Se3 x, and Bi2−2 x Sb2 x Se3, are studied, and a sudden change in several properties, including optical absorption ε2 (ω), optical dielectric constant ε∞, Born effective charge Z *, electrical conductivity, as well as bond breaking behavior for a critical Se or Sb concentration, is evidenced. These findings provide a blueprint to experimentally explore the influence of metavalent bonding on attractive properties of phase‐change materials and thermoelectrics. Particularly important is its impact on optical properties, which can be tailored by the amount of electrons shared between adjacent atoms. This correlation can be used to design optoelectronic materials and to explore systematic changes in chemical bonding with stoichiometry and atomic arrangement. Abstract : Metavalent bonding in solids is shown to differ significantly from covalent bonding, as demonstrated by pronounced property changes for optical, vibrational, electronic, and structural properties upon the transition from covalent to metavalent bonding. This insight and the resulting map showing trends in chemical bonding and material properties can be used to design and tailor materials.