Magnetostriction and magnetization measurements on a DyNi2B2C single crystal in a magnetic field

In order to investigate the interactions between lattice properties, magnetic ordering and superconductivity of DyNi2B2C, thermal expansion, magnetostriction and magnetization measurements were performed for T = 2-15 K and for mu(0)H = 0-3 T on a single crystal in the crystallographic [1 1 0] direction. A magnetic phase diagram is derived that shows two phases (AF1 and AF2) in the narrow region between the zero-field antiferromagnetic AF and the induced ferromagnetic state FM. Moreover, it is characterized by a large-field hysteresis, This behaviour can be described by a two domain magnetic state. The metamagnetic structure AF1 with about a quarter of the saturated magnetization is responsible for suppressing the superconductivity in DyNi2B2C because of its ferromagnetic component. (C) 1999 Elsevier Science B.V. All rights reserved.