Critical current density and flux pinning in La2-xPrxCa2xBa2Cu4+2xOz (x = 0.1 - 0.5) superconductors

TL;DR

This study investigates how doping in La2-xPrxCa2xBa2Cu4+2xOz superconductors affects their structure, critical temperature, and flux pinning, revealing that ion substitution enhances critical current density.

Contribution

It demonstrates that ion substitution in LPCaBCO compounds increases flux pinning and critical current density, advancing understanding of superconducting properties.

Findings

Critical temperature increases from 32 to 62 K with doping.

Unit cell volume shrinks due to ion substitution.

Flux pinning improves with increased dopant concentration.

Abstract

Polycrystalline La2-xPrxCa2xBa2Cu4+2xOz (LPCaBCO) compounds with x = 0.1 - 0.5 were synthesized by solid-state reaction method and studied by room temperature X-ray diffraction, dc resistivity, dc magnetization and iodometry. The superconducting transition temperatures in these tetragonal triple perovskite compounds increases from 32 to 62 K (Tconset values) with increasing dopant concentration. The mixing of rare earth La3+ and Pr3+/4+ ions at rare earth site (La3+) along with substitution of divalent Ca2+ results in the shrinkage of unit cell volume. The contraction of unit cell volume due to larger ion being substituted by smaller ions, gives rise to creation of pinning centers in the unit cell leading to increase in critical current density and flux pinning