Pinning and Dynamics of Magnetic Flux Moving Across the Twin Planes in YBa_2Cu_3O_6.97 Single Crystal

TL;DR

This study investigates how magnetic flux vortices move and are pinned in YBa2Cu3O6.97 single crystals, revealing how the pinning force and vortex dynamics change with magnetic field variations.

Contribution

It provides new insights into the field-dependent pinning force and vortex motion behavior across twin boundaries in high-temperature superconducting crystals.

Findings

Depinning current J_c decreases as magnetic field increases.

Vortex velocity weakly decreases with increased magnetic field at low currents.

Pinning force reduction correlates with fewer vortex lines trapped by twin boundaries.

Abstract

We present the transport studies of field variation of the pinning force for the flux motion across the twin boundaries in YBaCuO single crystals. It is found that the depinning current J_c decreases with an increase in the magnetic field due to reduction of the portion of vortex lines trapped by the TB's. However, at transport currents J << J_c, the vortex velocity weakly decreases with the increased field, i.e. it is determined mainly by the release of the vortex lines from the TB's.