Pressure-Induced Superconductivity and Its Scaling with Doping-Induced Superconductivity in the Iron Pnictide with Skutterudite Intermediary Layers

TL;DR

This study explores pressure-induced superconductivity in a new iron pnictide compound, revealing how pressure suppresses antiferromagnetism and induces superconductivity with a dome-shaped transition temperature.

Contribution

It demonstrates the emergence of superconductivity under pressure in a novel iron pnictide with skutterudite layers, linking pressure effects to doping-induced superconductivity.

Findings

Superconductivity appears between 3.5-7 GPa after suppressing AFM order.

Superconducting transition temperature exhibits a dome-shaped dependence on pressure.

Undoped 10-3-8 is an AFM semiconductor, while 10-4-8 is superconducting at ambient conditions.

Abstract

The Ca10(PtnAs8)(Fe2As2)5 (n=3,4) compounds are a new type of iron pnictide superconductors whose structures consist of stacking Ca-PtnAs8-Ca-Fe2As2 layers in a unit cell. When n=3 (the 10-3-8 phase), the undoped compound is an antiferromagnetic (AFM) semiconductor, while, when n=4 (the 10-4-8 phase), the undoped compound is a superconductor with the transition temperature of 26K. Here we report the results of high-pressure studies on the 10-3-8 compound obtained through a combination of in-situ resistance, magnetic susceptibility, and Hall coefficient measurements. We find that its AFM order can be suppressed completely at 3.5 GPa and then superconducting state appears in the pressure range of 3.5-7 GPa. The pressure dependence of superconducting transition temperature displays a dome-like shape.