First Homologous Series of Iron Pnictide Oxide Superconductors (Fe2As2)(Can+1(Sc,Ti)nOy) [n = 3,4,5] with Extremely Thick Blocking Layers

TL;DR

This paper reports the discovery of a new homologous series of iron pnictide oxide superconductors with thick blocking layers, exhibiting bulk superconductivity up to 42 K and revealing insights into the relationship between structure and Tc.

Contribution

The study introduces the first homologous series of iron pnictide oxide superconductors with thick layers, expanding the understanding of structure-property relationships in these materials.

Findings

Discovered new homologous series of Fe-based superconductors.

Achieved bulk superconductivity with Tc up to 42 K.

Identified correlation between interlayer distance and Tc.

Abstract

We have discovered first homologous series of iron pnictide oxide superconductors (Fe2As2)(Can+1(Sc,Ti)nOy) [n = 3,4,5]. These compounds have extremely thick blocking layers up to quintuple perovskite oxide layers sandwiched by the Fe2As2 layers. These samples exhibited bulk superconductivity with relatively high Tc up to 42 K. The relationship between Tc and the iron-plane interlayer distance suggested that superconductivity due to the mono Fe2As2 layer is substantially 40 K-class.