New ternary ThCr2Si2-type iron-selenide superconducting materials: synthesis, properties and simulations

TL;DR

This paper reviews recent advances in synthesizing and understanding ThCr2Si2-type iron-selenide superconductors, highlighting their properties, new compositions, and theoretical insights into their electronic and magnetic behaviors.

Contribution

It provides a comprehensive overview of the synthesis, experimental properties, and theoretical data of newly discovered iron-selenide superconductors in the 122 family.

Findings

Superconductivity observed at 28-32 K in various 122-type iron-selenide compounds.

Successful synthesis of new ternary ThCr2Si2-type iron-selenide materials.

Theoretical studies reveal electronic and magnetic properties relevant to superconductivity.

Abstract

Very recently (November, 2010, PRB, 82, 180520R), the first ThCr2Si2-type ternary superconductor K0.8Fe2Se2 with enhanced TC ~ 31 K has been discovered. This finding has stimulated much activity in search for related materials and triggered intense studies of their properties. Indeed, very soon superconductivity (TC ~ 28-32 K) was also found in the series of related ternary systems (so-called 122 phases) such as CsxFe2-ySe2, RbxFe2-ySe2, (TlK)xFeySe2, (TlRb)xFeySe2 etc., which formed a new group of superconducting iron-based materials without toxic As. In this paper the recent progress in synthesis of 122-like iron-selenide systems and in experimental research of their properties is reviewed. Available theoretical data on electronic, magnetic, and elastic properties of this newest group of superconducting materials are also discussed.