Magnetic Transport Properties in GdBa2Cu3−x Ru x O7−δ Superconducting Phase

Abstract

Bulk superconducting samples of type GdBa2Cu3−xRuxO7−δ phase, Gd-123, with x ranging from 0.0 to 0.15 were prepared by the conventional solid-state reaction technique. X-ray powder diffraction (XRD) and the electrical resistivity measurements were performed in order to investigate the effect of Ru4+ ions substitution on Gd-123 phase. Enhancement of the phase formation and the superconducting transition temperature Tc for GdBa2Cu3−xRuxO7−δ phase up to x=0.05 was observed. The effect of magnetic field up to 4.4 kG on the electrical resistivity behavior of the prepared samples was studied to investigate the flux motion of this phase. The derived flux pinning energy U, based on the thermally activated flux creep TAFC model, decreased with increasing the magnetic field B. The flux pinning energy followed the exponent behavior as U(B)∼B−β. The superconducting transition width ΔT increased as the magnetic field increased, showing the scaling relation as ΔT∼Bn. Using Ambegaokar and Halperin AH theory, the magnetic field and temperature dependence of U was found to be U(B,T)∼ΔTB−η, η=β+n. The critical current density Jc(0) enhanced up to x=0.05, beyond which it decreased with further increase in Ru-content.