Recent Advances in Layered Metal Chalcogenides as Superconductors and Thermoelectric Materials: Fe-Based and Bi-Based Chalcogenides

摘要

Recent advances in layered (Fe-based and Bi-based) chalcogenides as superconductors or functional materials are reviewed. The Fe-chalcogenide (FeCh) family are the simplest Fe-based high-T-c superconductors. The superconductivity in the FeCh family is sensitive to external or chemical pressure, and high T-c is attained when the local structure (anion height) is optimized. The Bi-chalcogenide (BiCh(2)) family are a new group of layered superconductors with a wide variety of stacking structures. Their physical properties are also sensitive to external or chemical pressure. Recently, we revealed that the emergence of superconductivity and the T-c in this family correlate with the in-plane chemical pressure. Since the flexibility of crystal structure and electronic states are an advantage of the BiCh(2) family for designing functionalities, I briefly review recent developments in this family as not only superconductors but also other functional materials.