Vortex creep and critical current densities in superconducting (Ba,K)Fe${}_2$As${}_2$ single crystals

Abstract

The surprisingly rapid relaxation of the sustainable current density in the critical state of single crystalline Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ is investigated for magnetic fields oriented parallel to the c-axis and to the $ab$--plane respectively. Due to the inadequacy of standard analysis procedures developed for flux creep in the high temperature superconducting cuprates, we develop a simple, straightforward data treatment technique that reveals the creep mechanism and the creep exponent $\mu$. At low magnetic fields, below the second magnetization peak, $\mu$ varies only slightly as function of temperature and magnetic flux density $B$. From the data, we determine the temperature- and field dependence of the effective activation barrier for creep. At low temperatures, the measured current density approaches the zero--temperature critical current density (in the absence of creep) to within a factor 2, thus lending credence to earlier conclusions drawn with respect to the pinning mechanism. The comparable values of the experimental screening current density and the zero-temperature critical current density reveals the limited usefulness of the widely used "interpolation formula".

Physical Review B (2012) Accepted

References in corpus (19)

• Elastic theory of flux lattices in presence of weak disorder
• Elastic Theory of pinned flux lattices
• Vortex phase diagram of Ba(Fe0.93Co0.07)2As2 single crystals
• Strong Pinning in High Temperature Superconductors
• Fishtail effect and the vortex phase diagram of single crystal Ba0.6K0.4Fe2As2
• Flux dynamics and vortex phase diagram in $Ba(F{e}_{1-x}C{o}_x{)}_{2}A{s}_2$ single crystals revealed by magnetization and its relaxation
• Very strong intrinsic supercurrent carrying ability and vortex avalanches in (Ba,K)Fe2As2 superconducting single crystals
• Observation of Lattice and Andreev Bound States of Vortices in Ba0.6K0.4Fe2As2 Single Crystals with Scanning Tunneling Microscopy/Spectroscopy
• Growth and characterization of A_{1-x}K_xFe_2As_2 (A = Ba, Sr) single crystals with x=0 - 0.4
• Flux pinning in (1111) iron-pnictide superconducting crystals
• Magnetization Relaxation and Collective Vortex Pinning in the Fe-Based Superconductor SmFeAsO_0.9F_0.1
• Flux-dynamics associated with the Second Magnetisation Peak in iron-pnictide Ba_{1-x}K_xFe_2As_2
• Charge doping-induced quasiparticle scattering in iron-pnictide superconductors as probed by vortex pinning
• Interactions, Distribution of Pinning Energies, and Transport in the Bose Glass Phase of Vortices in Superconductors
• Transport properties of BSCCO crystals with and without surface barriers
• Coulomb Gap and Correlated Vortex Pinning in Superconductors
• Strong pinning and vortex energy distributions in single crystalline Ba(Fe1-xCox)2As2
• Flux dynamics and vortex phase diagram of the new superconductor $Mg{B}_2$
• Magnetic relaxation in the "Bragg-glass" phase in BSCCO

Cited by in corpus (9)

• Doping-dependent critical current properties in K, Co, and P-doped BaFe2As2 single crystals
• Comparative study of vortex dynamics in CaKFe4As4 and Ba0.6K0.4Fe2As2 single crystals
• Disorder, critical currents, and vortex pinning energies in isovalently substituted BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Magnetization relaxation, critical current density and vortex dynamics in a Ba${}_{0.66}$K${}_{0.32}$BiO${}_{3+\delta }$ single crystal
• Vortex creep at very low temperatures in single crystals of the extreme type-II superconductor Rh${}_9$In${}_4$S${}_4$
• Effects of asymmetric splayed columnar defects on the anomalous peak effect in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$
• SANS Study of Vortex Lattice Structural Transition in Optimally Doped (Ba${}_{1-x}$K${}_x$)Fe${}_2$As${}_2$
• Effect of controlled artificial disorder on the magnetic properties of EuFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ ferromagnetic superconductor
• Thermal creep emerging from cooling a tilted vortex lattice in uniaxial superconductor