Pressure versus concentration tuning of the superconductivity in Ba(Fe(1-x)Cox)2As2

TL;DR

This study compares pressure and chemical doping as methods to induce superconductivity in BaFe2As2, revealing that pressure can tune Tc similarly to chemical substitution without introducing disorder.

Contribution

It provides a direct comparison of pressure and chemical doping effects on superconductivity and structural features in BaFe2As2, highlighting their quantitative relationship.

Findings

Tc(p) tracks Tc(x) for different Co doping levels

Pressure induces superconductivity without lattice disorder

Structural changes under pressure resemble chemical doping effects

Abstract

In the iron arsenide compound BaFe2As2, superconductivity can be induced either by a variation of its chemical composition, e.g., by replacing Fe with Co, or by a reduction of the unit-cell volume through the application of hydrostatic pressure p. In contrast to chemical substitutions, pressure is expected to introduce no additional disorder into the lattice. We compare the two routes to superconductivity by measuring the p dependence of the superconducting transition temperature Tc of Ba(Fe(1-x)Cox)2As2 single crystals with different Co content x. We find that Tc(p) of underdoped and overdoped samples increases and decreases, respectively, tracking quantitatively the Tc(x) dependence. To clarify to which extent the superconductivity relies on distinct structural features we analyze the crystal structure as a function of x and compare the results with that of BaFe2As2 under pressure.