A New Three-Dimensional Subsulfide Ir2In8S with Dirac Semimetal Behavior

• Published in: Journal of the American Chemical Society Vol. 141; no. 48; pp. 19130 - 19137
• Main Authors: Khoury, Jason F, Rettie, Alexander J. E, Khan, Mojammel A, Ghimire, Nirmal J, Robredo, Iñigo, Pfluger, Jonathan E, Pal, Koushik, Wolverton, Chris, Bergara, Aitor, Jiang, J. S, Schoop, Leslie M, Vergniory, Maia G, Mitchell, J. F, Chung, Duck Young, Kanatzidis, Mercouri G
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 04.12.2019; American Chemical Society (ACS)
• Subjects: indium; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; iridium; metalloids; prediction; sulfides
• DOI: 10.1021/jacs.9b10147
• ISSN: 0002-7863; 1520-5126

Dirac and Weyl semimetals host exotic quasiparticles with unconventional transport properties, such as high magnetoresistance and carrier mobility. Recent years have witnessed a huge number of newly predicted topological semimetals from existing databases; however, experimental verification often lags behind such predictions. Common reasons are synthetic difficulties or the stability of predicted phases. Here, we report the synthesis of the type-II Dirac semimetal Ir2In8S, an air-stable compound with a new structure type. This material has two Dirac crossings in its electronic structure along the Γ–Z direction of the Brillouin zone. We further show that Ir2In8S has a high electron carrier mobility of ∼10 000 cm2/(V s) at 1.8 K and a large, nonsaturating transverse magnetoresistance of ∼6000% at 3.34 K in a 14 T applied field. Shubnikov de-Haas oscillations reveal several small Fermi pockets and the possibility of a nontrivial Berry phase. With its facile crystal growth, novel structure type, and striking electronic structure, Ir2In8S introduces a new material system to study topological semimetals and enable advances in the field of topological materials.