BaTh$_2$Fe$_4$As$_4$(N$_{0.7}$O$_{0.3}$)$_2$: An Iron-Based Superconductor Stabilized by Inter-Block-Layer Charge Transfer

TL;DR

This paper reports the synthesis of a new iron-based superconductor stabilized by inter-layer charge transfer, exhibiting bulk superconductivity at approximately 22 K, and highlights the importance of charge transfer in its stability.

Contribution

The study introduces a novel electron-doped 12442-type superconductor stabilized through inter-block-layer charge transfer, expanding the understanding of structural design in iron-based superconductors.

Findings

Superconductor synthesized with T_c around 22 K

Inter-layer charge transfer stabilizes the compound

Dominant electron conduction observed

Abstract

Recently, An electron-doped 12442-type iron-based superconductor BaTh$_2$Fe$_4$As$_4$(N$_{0.7}$O$_{0.3}$)$_2$ has been successfully synthesized with high-temperature solid-state reactions on basis of a structural design. The inter-block-layer charge transfer between the constituent units of "BaFe$_2$As$_2$" and "ThFeAsN$_{0.7}$O$_{0.3}$" was found to be essential to stabilize the target compound. Dominant electron-type conduction and bulk superconducting transition at ~22 K were demonstrated.