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

Abstract

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-Tc superconductors. The superconductivity in the FeCh family is sensitive to external or chemical pressure, and high Tc is attained when the local structure (anion height) is optimized. The Bi-chalcogenide (BiCh2) 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 Tc in this family correlate with the in-plane chemical pressure. Since the flexibility of crystal structure and electronic states are an advantage of the BiCh2 family for designing functionalities, I briefly review recent developments in this family as not only superconductors but also other functional materials.

Layered manganese bismuth tellurides with GeBi4Te7- and GeBi6Te10-type structures: towards multifunctional materials

“…These include topologically non-trivial electronic structures, charge-density waves, superconductivity or promising thermoelectric properties. [1][2][3][4][5][6][7] For thermoelectric wasteheat recovery and Peltier cooling near room temperature (RT), the layered semiconductor Bi 2 Te 3 and its substitution variants with Sb and Se are used in technical applications. 8 The thermoelectric performance of Bi 2 Te 3 has been optimized e.g.…”

Bulk Superconductivity Induced by Se Substitution in BiCh2-Based Layered Compounds Eu0.5Ce0.5FBiS2−xSex

“…There has been considerable interest in the study of BiCh2-based (Ch: S, Se) layered compounds because of their unique functionalities including superconductivity, thermoelectricity, and so forth [1]. The layered crystal structure of the BiCh2-based system consists of conducting BiCh2 layers alternating with electrically insulating (blocking) layers, which resembles those of cuprate or Fe-based high-transitiontemperature (Tc) superconductors [2,3].…”

“…The layered crystal structure of the BiCh2-based system consists of conducting BiCh2 layers alternating with electrically insulating (blocking) layers, which resembles those of cuprate or Fe-based high-transitiontemperature (Tc) superconductors [2,3]. Since the discovery of superconductivity in Bi4O4S3 and REO1xFxBiS2 (RE: rare-earth element), several types of BiCh2-based superconductors have been reported [1,4,5]. Although many experimental and theoretical studies have been devoted to clarify the superconductivity mechanism and to increase the Tc of the BiCh2-based superconductors, the consensus on the nature of superconductivity is yet to be achieved.…”

Layered Manganese Bismuth Tellurides with GeBi4Te7– and GeBi6Te10–type Structures: Towards Multifunctional Materials

“…These include topologically nontrivial electronic structures, charge-density waves, superconductivity or promising thermoelectric properties. [1][2][3][4][5][6][7] For thermoelectric waste-heat recovery and Peltier cooling near room temperature (RT), the layered semiconductor Bi 2 Te 3 and its substitution variants with Sb and Se are used in technical applications. 8 The thermoelectric performance of Bi 2 Te 3 has been optimized e.g.…”

“…Fig 5. Crystal structures of a) Mn0.81Bi6.13Te10 with GeBi6Te10-type structure; b) Mn0.85Bi4.10Te7 with GeBi4Te7-type structure; c) Mn0.85Bi2.1Te432 with GeBi2Te4-type structure; d)…”