Superconductivity at 17 K in (Fe2P2)(Sr4Sc2O6): a new superconducting layered pnictide oxide with a thick perovskite oxide layer

TL;DR

This paper reports the synthesis of a new layered iron-based oxypnictide that exhibits superconductivity at 17 K, featuring a unique structure with the longest interlayer Fe-Fe distance among similar compounds.

Contribution

It introduces a novel layered pnictide oxide with a thick perovskite layer and demonstrates its superconducting properties at 17 K, surpassing previous arsenic-free iron-based superconductors.

Findings

Superconductivity observed below 17 K.

Unique layered structure with longest interlayer Fe-Fe distance.

Higher transition temperature than similar arsenic-free systems.

Abstract

A new layered oxypnictide (Fe2P2)(Sr4Sc2O6) have been synthesized by solid-state reaction. This material has an alternating layer stacking structure of anti-fluorite Fe2P2 and perovskite-based Sr4Sc2O6 oxide layers. Space group of the material is P4/nmm and lattice constants a and c are 4.016 A and 15.543 A, respectively. The interlayer Fe-Fe distance corresponding to the c-axis length is the longest ever reported in the iron-based oxypnictide systems. In both magnetization and resistivity measurements, the present compound exhibited superconductivity below 17 K, which is much higher than that of LaFePO and the highest in arsenic-free iron-based oxypnictide systems under ambient pressure.