Superconductivity and the magnetic phase diagram of DyNi2B2C at very low temperatures

Detailed measurements of the resistivity rho(ab) as a function of temperature, magnetic field and orientation have been carried out on single crystals of tetragonal bodycentered DyNi2B2C. From the angular dependence of the metamagnetic transitions a magnetic phase diagram has been obtained. For B\\[100], an anomalously large hysteresis effect of the metamagnetic and also of the superconducting transitions were observed in the low temperature range (T < 2 K). This large hysteresis leads to a reentrant behavior of the superconductivity in small external fields, which indicate a strong interplay between magnetism and superconductivity in DyNi2B2C. (C) 1999 Elsevier Science B.V. All rights reserved.