Enhanced magnetic ordering by impurity Fe substitution on electron-doped superconductors Eu2-x+yCex-yCu1-yFeyO4+α-δ

Abstract

Crystal structure and magnetic properties are two important properties of superconducting materials that need to be studied. We partially substituted the Cu with a magnetic impurity Fe in the electron-doped superconducting cuprate of Eu2-x+yCex-yCu1-yFeyO4+α-δ (ECCFO) to investigate the effect of Fe impurity substitution on crystal structure and magnetic properties. In this study, we have chosen concentrations of x = 0.12 and 0.15, and concentrations of y = 0.01, 0.02, and 0.05. The crystal structure was studied by analyzing XRD patterns, and magnetic properties were analyzed using data obtained from susceptibility measurements. For y = 0, the lattice parameter a and Cu–O(2) bond length increased with increasing x from 0.12 to 0.15. It is confirmed by magnetic susceptibility measurement that the Tc of x = 0.15 (14 K) is larger than that of x = 0.12 (12 K). For the effect of the addition of Fe on the structural parameters, the lattice parameter c increased with the addition of Fe, which means the distance between the charge reservoir and the conducting layer is getting farther. The addition of Fe to the ECCFO sample increased the C and μeff values. This is because Fe impurity causes an increase in the magnetic ordering of the ECCFO material and reduces its superconductivity.

Keywords

• Cu-O bond length
• Eu-O bond length
• Eu2-x+yCex-yCu1-yFeyO4+α-δ
• Fe impurities
• Tc