Enhancement of the Critical Current Density of YBa2Cu3Ox Superconductors under Hydrostatic Pressure

TL;DR

This study investigates how applying hydrostatic pressure up to 0.6 GPa significantly increases the critical current density in YBa2Cu3Ox superconductors, revealing oxygen vacancies' role in limiting performance.

Contribution

It introduces a new diagnostic method, pressure-induced Jc relaxation, to analyze oxygen vacancies and suggests oxygen filling as a way to enhance superconducting properties.

Findings

Jc increases by 20% per GPa under pressure

Vacant oxygen sites are identified as limiting factors

Filling oxygen vacancies could significantly improve Jc

Abstract

The dependence of the critical current density Jc on hydrostatic pressure to 0.6 GPa is determined for a single 25-degree [001]-tilt grain boundary in a bicrystalline ring of nearly optimally doped melt-textured YBa2Cu3Ox. Jc is found to increase rapidly under pressure at +20 %/GPa. A new diagnostic method is introduced (pressure-induced Jc relaxation) which reveals a sizeable concentration of vacant oxygen sites in the grain boundary region. Completely filling such sites with oxygen anions should lead to significant enhancements in Jc.