Effects of Ru Addition on the Superconducting Properties of the Eu-123 System

Abstract

Eects of the Ru addition on the structural and superconducting properties of the Eu-123 system were studied. Samples of the nominal composition EuBa2Cu3−xRuxO 7−δ with x ranging from 0.0 to 0.7 were prepared by the solid state reaction technique from Eu2O3, BaCO3, CuO and RuO2 precursors at the temperature of 1050• C for 72 h in owing oxygen and oxygen-annealed at 580• C for 24 h. X-ray diraction data show the presence of another BaEuRuO phase, for x ≥ 0.03, in addition to the main superconducting phase. AC and DC magnetization characteristics were measured by the compensation method using the second-order SQUID gradiometer at ≈ 77 K and the QD SQUID magnetometer MPMS XL-7 at 20 K. The superconducting properties, Tc, ∆Tc, change only weakly up to x = 0.2, and magnetization M (H) deteriorates with an increasing Ru content.