Magnetic Properties and Critical Currents of the Dy0.8Er0.2Rh3.8Ru0.2B4< /sub> and Dy0.6Er0.4Rh3.8Ru0.2B4< /sub> Superconductors

The magnetic superconductors Dy0.8Er0.2Rh3.8Ru0.2B4 (T-c similar to 5.1 K) and Dy0.6Er0.4Rh3.8Ru0.2B4 (T-c similar to 5.8 K) have been prepared by partially substituting Er for Dy in DyRh3.8Ru0.2B4, and their chi(T), M(B), and B-c2(T) have been studied in detail. The materials have been shown to undergo an antiferromagnetic transition (at similar to 3 K) similar to that of the magnetic superconductor DyRh3.8Ru0.2B4. Using magnetic moment vs. magnetic field, M(B), measurements for Dy0.8Er0.2Rh3.8Ru0.2B4 and Dy0.6Er0.4Rh3.8Ru0.2B4 samples and the Bean model, we have obtained the critical current density as a function of field, j(c)(B), and the reduced pinning force as a function of reduced field, F-p(h), for the Er-containing materials. The superconductors with antiferromagnetic order in their magnetic subsystem (Dy0.8Er0.2Rh3.8Ru0.2B4 and Dy0.6Er0.4Rh3.8Ru0.2B4) have been shown to exhibit the largest deviation from the scaling law for h > 0.4.