Coexistence of superconductivity and magnetic ordering in the Y1-xRExNi2B2C (RE=Gd, Dy, Ho, Er) system

The magnetic and superconducting properties of the intermetallic compounds Y1-xRExNi2B2C (RE = Gd, Dy, Ho, Pr; 0 less than or equal to x less than or equal to 1.0) have been measured over wide temperature and magnetic field ranges. The existence of the RE3+ paramagnetic ions causes the depression of superconductivity, which can be well interpreted by the Abrikosov-Gor'kov magnetic pair-breaking theory. The corresponding magnetic-ordering temperature increases with increasing magnetic moment concentration while the superconducting transition temperature decreases. The long-range magnetic-ordering is mainly caused by the Ruderman-Kittel-Kasuya-Yosida indirect exchange interaction via conduction electrons. This indirect exchange coupling strongly depends on the RE3(+)-moment separation and de Gennes factor. This experiment demonstrates that coexistence of long-range magnetic-ordering and superconductivity in Y1-xRExNi2B2C compounds is possible. (C) 1998 Elsevier Science Ltd. All rights reserved