Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs

TL;DR

This study reports the discovery of superconductivity up to 37 K in a new Fe-based compound system, highlighting the importance of FeAs layers and elemental A-layers in achieving high Tc.

Contribution

The paper introduces a new family of Fe-based superconductors with Tc up to 37 K, emphasizing the role of electron doping and elemental layers in enhancing superconductivity.

Findings

Superconductivity observed up to 37 K in (A1-xSrx)Fe2As2 with A=K, Cs

Electron doping induces a transition to a spin-density-wave state

FeAs layers are crucial for superconductivity

Abstract

A new hight Tc Fe-based compound system, AFe2As2 with A = K, Cs, K/Sr and Cs/Sr has been found. Through electron-doping, Tc of the A = K and Cs compounds rises to ~37 K, and finally enter a spin-density-wave state (SDW) through further electron doping with Sr. The observation demonstrates the crucial role of the (FeAs)-layers in the superconductivity in the Fe-based layered system and the special feature of elemental A-layers in this complex chemical system may provide new avenues to superconductivity at a higher Tc.