Data for: Tripling of the Superconducting Critical Current Density in BaFe2(As(1-x)Px)2 Retained After Pressure Release

Description

Superconducting performance is tunable not only via chemical modification or defect engineering, but also through external parameters such as pressure, though this method remains less readily accessible. In this work, we study how compression influences vortex dynamics and critical currents in an iron-based superconductor. Specifically, we perform magnetization measurements using an off-the-shelf pressure cell to investigate the effects of hydrostatic pressures up to 1.08 GPa on the magnetic properties of BaFe$_2$(As$_{0.62}$P$_{0.38}$)$_2$ crystals across a range of temperatures $T$ and magnetic fields $H$. Although these pressures minimally affect the superconducting critical temperature, they produce a clear increase in the critical current density $J_c(T,H)$, a pronounced reduction in the rate of thermally activated vortex motion $S(T,H)$, and can change the dominant vortex pinning mechanism. Furthermore, the effects of pressure are irreversible: after pressurization and subsequent release at room temperature, high-density microcracks are observed and the crystals retain their enhanced critical current densities. The second magnetization peak vanishes above 18 K after the pressure cycle, which we attribute to a transition from predominantly $\delta \kappa$ pinning to a mixed mechanism of $\delta T_c$ and surface pinning. Lastly, a threefold increase in $J_c$, a more than 40\% reduction in $S$ at 8~K and 0.5~T, and an expanded elastic-creep region were achieved after $1-2$ pressure cycles. These findings demonstrate the potential utility of pressure cycling for improving $J_c$, which may offer a simpler alternative to approaches such as chemical doping or the introduction of artificial pinning centers. This dataset includes Python code used to process the data and Origin files (.opju) that contain data spreadsheets for all the samples and figures used in this paper, which can be opened using Origin Viewer, a free application that permits viewing and copying of data contained in Origin project files.

Institutions

• University of Washington

  WA, Seattle
• University of California Los Angeles

  CA, Los Angeles
• Pacific Northwest National Laboratory

  Washington, Richland

Categories

Funders

• UW Molecular Engineering Materials Center

  Grant ID: DMR-2308979

Licence