Thermodynamic approach for enhancing superconducting critical current performance

Abstract

The addition of artificial pinning centers has led to an impressive increase in critical current density ($J_{\mathrm{c}}$) in a superconductor, enabling record-breaking all-superconducting magnets and other applications. $J_{\mathrm{c}}$ has reached $\sim 0.2$-$0.3$ $J_{\mathrm{d}}$, where $J_{\mathrm{d}}$ is the depairing current density, and the numerical factor depends on the pinning optimization. By modifying $\lambda$ and/or $\xi$, the penetration depth and coherence length, respectively, we can increase $J_{\mathrm{d}}$. For (Y${}_{0.77}$Gd${}_{0.23}$)Ba${}_2$Cu${}_3$O${}_y$ ((Y,Gd)123) we achieve this by controlling the carrier density, which is related to $\lambda$ and $\xi$. We also tune $\lambda$ and $\xi$ by controlling the chemical pressure in the Fe-based superconductors, BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ films. The variation of $\lambda$ and $\xi$ leads to an intrinsic improvement of $J_{\mathrm{c}}$, via $J_{\mathrm{d}}$, obtaining extremely high values of $J_{\mathrm{c}}$ of $130$ MA/cm${}^2$ and $8.0$ MA/cm${}^2$ at $4.2$ K, consistent with an enhancement of $J_{\mathrm{d}}$ of a factor of $2$ for both incoherent nanoparticle-doped (Y,Gd)123 coated conductors (CCs) and BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ films, showing that this new material design is useful to achieving high critical current densities for a wide array of superconductors. The remarkably high vortex-pinning force in combination with this thermodynamic and pinning optimization route for the (Y,Gd)123 CCs reached $\sim 3.17$ TN/m${}^3$ at $4.2$ K and 18 T ($\mathbf{H}\parallel c$), the highest values ever reported in any superconductor.

arXiv comment35 pages, 7 figures

References in corpus (16)

• Strongly Enhanced Current Densities in Superconducting Coated Conductors of YBa2Cu3O7-x + BaZrO3
• Evaluation of CuO2 plane hole doping in YBa2Cu3O6+x single crystals
• A Sharp Peak of the Zero-Temperature Penetration Depth at Optimal Composition in BaFe2(As1-xPx)2
• Direct measurement of the upper critical field in a cuprate superconductor
• Quasiparticle mass enhancement approaching optimal doping in a high-Tc superconductor
• Electromagnetic, atomic-structure and chemistry changes induced by Ca-doping of low-angle $YB{a}_{2}C{u}_3{O}_{7-\delta }$ grain boundaries
• Absolute values of the London penetration depth in YBa2Cu3O6+y measured by zero field ESR spectroscopy on Gd doped single crystals
• Ultra-high critical current densities of superconducting YBa${}_2$Cu${}_3$O${}_{7-\delta }$ thin films in the overdoped state
• Josephson-like behavior in YBa${}_2$Cu${}_3$O${}_{7-\delta }$ nano-bridges carrying the depairing current
• Universal Lower Limit on Vortex Creep in Superconductors
• Beneficial influence of Hf and Zr additions to Nb4at.%Ta on the vortex pinning of Nb${}_3$Sn with and without an O source
• Hole-pocket-driven superconductivity and its universal features in the electron-doped cuprates
• Targeted evolution of pinning landscapes for large superconducting critical currents
• Critical Current Distributions of Recent Bi-2212 Round Wires
• Rapid change of electronic anisotropy in overdoped (Y,Ca)Ba2Cu3O7-d
• Relationships between Superconductivity and Nematicity in FeSe${}_{1-x}$Te${}_x$ ($x=0-0.5$) Films Studied by Complex Conductivity Measurements

Cited by in corpus (4)

• Oxygen incorporation in YBa${}_2$Cu${}_3$O${}_{7-\delta }$ thin films: surface activation and degradation
• Boost of critical current density near quantum critical points in FeSe-Based superconductors with two superconducting domes
• Impurity-controlled vortex mobility and pair-breaking in fermionic superfluid rings
• Higher critical currents yet faster vortex creep in EuBa${}_2$Cu${}_3$O${}_y$ films containing coherent artificial pinning centers