High intrinsic flux pinning strength of BaFe2-xCoxAs2 superconductor

TL;DR

This study investigates the flux pinning potential in BaFe2-xCoxAs2 superconductors, revealing strong intrinsic flux pinning properties and the transition from individual to collective pinning with increasing magnetic field.

Contribution

It provides detailed analysis of flux pinning behavior across doping levels and magnetic field orientations, highlighting the superconductor's high intrinsic flux pinning strength.

Findings

U0 exhibits power law dependence on magnetic field.

Individual flux pinning dominates up to certain fields, then transitions to collective pinning.

BaFe2-xCoxAs2 shows higher flux pinning potential compared to some other superconductors.

Abstract

The field dependence of flux pinning potential, U0, for under-doped, optimally doped and over-doped Ba(Fe,Co)2As2 single crystals has been investigated. U0 is determined using the Thermally Activated Flux Flow (TAFF) model, for both H || ab and H || c configurations. The observed power law dependencies of U0 versus H suggest that for fields upto 12 T for H || ab and 7 T for H || c, individual flux pinning, and for fields beyond 7 T for H || c, collective pinning becomes operative. A comparison of U0 for the Ba(Fe,Co)2As2 system with some other superconductors is presented