Magnetostructural transition in NdCu2 - Evidence for an axis conversion like behaviour

The magnetic (H, T)-phase diagram of the orthorhombic compound NdCu2 was in vestigated for external magnetic fields up to 15 T parallel to the crystall ographic c-direction. Magnetization and magnetostriction measurements revea l an anomalous change of the magnetic properties as well as giant magnetost riction (GMS) and large hysteretic effects. This behaviour similar to that observed in some other RCu2 compounds where it has been interpreted as a co nversion of the magnetic Ising axis. In contract to these other RCu2 compou nds, however, the easy axis of magnetization in NdCu2 is the b-axis. The ma croscopic measurements are compared with neutron diffraction experiments wh ich reveal GMS along the b-axis and a new magnetic phase with propagation v ector tau = (0.700) in the converted crystal.