Microwave properties of $(Pr_xY_{1-x})Ba_2Cu_3O_{7-\delta}$ : Influence of magnetic scattering

TL;DR

This study investigates how magnetic Pr doping affects the microwave surface impedance and superconducting properties of YBCO, revealing magnetic scattering impacts and pairbreaking effects.

Contribution

It provides new insights into magnetic scattering effects on superconductivity in Pr-doped YBCO through detailed impedance measurements.

Findings

Multiple transition structures in $R_s(T)$

High residual resistance with increased Pr

Low T behavior shifts to $T^4$ at high Pr doping

Abstract

We report measurements of the surface impedance $Z_s=R_s+iX_s$ of $(Pr_xY_{1-x})Ba_2Cu_3O_{7-\delta}$, $(x=0,0.15,0.23,0.3,0.4,0.5)$. Increasing $Pr$ concentration leads to some striking results not observed in samples doped by non-magnetic constituents. The three principal features of the $R_s(T)$ data - multiple structure in the transition, a high residual resistance and, at high $Pr$ concentrations, an upturn of the low $T$ data, are all characteristic of the influence of magnetic scattering on superconductivity, and appear to be common to materials where magnetism and superconductivity coexist. The low $T$ behavior of $\lambda (T)$ appears to change from $T$ to $T^4$ at large $Pr$ doping, and provides evidence of the influence of magnetic pairbreaking of the $Pr$.