Pressure Induced Superconductivity in Ba0.5Sr0.5Fe2As2

TL;DR

This study demonstrates that Ba0.5Sr0.5Fe2As2 exhibits pressure-induced superconductivity, with a maximum transition temperature around 31 K at 3.3 GPa, and the superconducting state disappears above 12 GPa.

Contribution

First experimental evidence showing pressure-induced superconductivity in a Ba/Sr 122-type iron arsenide solid solution.

Findings

Superconductivity appears at ~3.3 GPa with Tc ~31 K.

Superconductivity vanishes above 12 GPa.

Pressure modulates the superconducting transition temperature.

Abstract

High-pressure electrical resistance measurements have been performed on single crystal Ba0.5Sr0.5Fe2As2 platelets to pressures of 16 GPa and temperatures down to 10 K using designer diamond anvils under quasi-hydrostatic conditions with an insulating steatite pressure medium. The resistance measurements show evidence of pressure-induced superconductivity with an onset transition temperature at ~31 K and zero resistance at ~22 K for a pressure of 3.3 GPa. The transition temperature decreases gradually with increasing in pressure before completely disappearing for pressures above 12 GPa. The present results provide experimental evidence that a solid solution of two 122-type materials, e.g., Ba1-x.SrxFe2As2 (0 < x <1), can also exhibit superconductivity under high pressure