Anisotropy of the superconducting state parameters and intrinsic pinning in low-level Pr-doped YBa2Cu3O(7-delta) single crystals

TL;DR

This study examines how low-level Pr doping affects the anisotropy and pinning in YBa2Cu3O(7-delta) superconductors, revealing that Pr influences vortex pinning without altering anisotropy.

Contribution

It provides new insights into the effects of Pr substitution on intrinsic pinning and anisotropy in high-temperature superconductors, using torque magnetometry.

Findings

Anisotropy parameter  of 7.4 is unaffected by Pr content up to 2.4%.

Intrinsic pinning is observed near 0.5-1 degree out of the ab-plane.

Pr content influences vortex pinning within CuO2 planes.

Abstract

The influence of low-level Pr substitution in Y1-xPrxBa2Cu3O(7-delta) single crystals on the anisotropy of the superconducting state parameters was investigated by torque magnetometry in magnetic fields of up to 9 T. An averaged anisotropy parameter, \gamma, of 7.4 was found and no influence of the Pr ion concentration on \gamma was observed up to a Pr content of 2.4%. A pronounced maximum at angles between 0.5 and 1 degree out of the ab-plane was observed in all crystals in the irreversible angular dependence of the torque. This maximum is attributed to intrinsic pinning associated with kinked vortices. The variation of the irreversible torque with the substitution level indicates the influence of the Pr content on pinning within the CuO2 planes, even though the anisotropy of the superconducting state parameters is not affected.