Superconductivity of rare-earth borides Dy1–xErxRh3.8Ru0.2B4 (x = 0, 0.2, 0.4) and Dy0.6Y0.4Rh3.85Ru0.15B4

Abstract

The effect on the superconductivity of the partial replacement of one magnetic rare-earth element (Dy) by another (Er) in rhodium borides Dy1–xErxRh3.8Ru0.2B4 with x = 0, 0.2, 0.4 is studied. It was found that in Dy1–xErxRh3.8Ru0.2B4, with increasing Er content, the temperature of the superconducting transition increases significantly: from 3.7 K for x = 0 to 6 K for x = 0.4. It was demonstrated that the replacement of magnetic Er3+ with nonmagnetic Y3+ in the isostructural compounds Dy0.6Er0.4Rh3.8Ru0.2B4 (Tc ≈ 6 K) and Dy0.6Y0.4Rh3.85Ru0.15B4 (Tc ≈ 7 K) does not lead to a significant change in the temperature of the superconducting transition. The suppression of the superconducting state by the magnetism of rare-earth elements is not observed down to 1.5 K the lowest available temperature in the experiment.