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DS: Fachverband Dünne Schichten
DS 3: Layer Properties
DS 3.5: Talk
Monday, March 18, 2024, 16:30–16:45, A 053
Electrical characterization of the pseudo-binary line In3SbTe2-SnTe — •Christian Stenz, Thomas Schmidt, Michael Dappen, and Matthias Wuttig — I. Institute of Physics (IA) RWTH Aachen University, Sommerfeldstraße 14, 52074 Aachen
Materials can be categorized by examining their properties, including band gap, effective coordination number, electrical and optical conductivity, Born effective charge, and more. Based on such properties and quantum chemical bond identifiers a classification into metallic, covalent, ionic, and metavalent bonding (MVB) appears appropriate. MVB is defined by a competition between electron localization and delocalization resulting in a unique property portfolio. SnTe and In3SbTe2 are identified to be metavalent and metallic, respectively. However, both occur in a rocksalt-like structure with similar lattice constants allowing for isostructural alloying. Investigating the property portfolio of the pseudo-binary line yields insights about the pronounced changes in properties by crossing the tipping point towards complete electron delocalization and closing the band gap. In this study several alloys on the pseudo-binary line In3SbTe2-SnTe are produced by sputter deposition. Properties like crystallization temperature Tx, electrical conductivity and superconducting transition temperature Tc are investigated. Upon the transition from MVB to metallic bonding a change in charge carrier type as well as a remarkable increase of Tc by 85 % and 1200 % compared to the pure compounds In3SbTe2 and SnTe, respectively, has been found.
Keywords: chemical bonding; electron (de-)localization; sputter deposition; crystallization temperature; superconducting transition temperature