Berlin 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
DS: Fachverband Dünne Schichten
DS 7: 2D Materials and their Heterostructures III
DS 7.2: Talk
Wednesday, March 20, 2024, 09:45–10:00, A 053
Classification of layered chalcogenides: explaining their mineral diversity in the Earth's crust — •Alexander Kiehn1, Carl-Friedrich Schön2, Christian Stenz2, Sebastian Gruner2, Jan Köttgen2, Jean-Yves Raty3, and Matthias Wuttig1,2 — 1PGI 10, Forschungszentrum Jülich; Johnen-Straße, 52428 Jülich, Germany — 2I. Institute of Physics (IA), RWTH Aachen University; Sommerfeldstraße 14, 52056 Aachen, Germany — 3CESAM, Université de Liège; Quartier Agora, Allée du six Août 19, 4000 Liège, Belgium
Layered or 2D chalcogenides are a material class with exceptional properties enabling manifold applications. Using quantum-chemical calculations, these materials can be classified into three families based on the distance between layers as well as the translation energy parallel to these layers. Containing many TMDCs, the largest group of layered chalcogenides forms van der Waals bonds across the gaps, which are characterized by large atomic spacings, small translation energies and weak interlayer bonding. Conversely, two other groups are identified by shorter interlayer gaps, larger translation energies and significantly stronger interlayer coupling. For several compounds, like Bi2Te3, these properties can be attributed to their special bonding mechanism. Notably, when combining compatible layer types into varying stacks, this large coupling allows for an energy hierarchy of interlayer bonding. This explains the rich phase diagrams of heavy p-block elements, like Sb, As, Bi and Te, and is also mirrored in their anomalously high mineral diversity. The evidence for strong interlayer coupling is supported by electron microscopy and laser-assisted bond-rupture experiments.
Keywords: transition metal dichalcogenides (TMDCs); 2D materials; layered chalcogenides; van der waals-like; metavalent bonding