The magnetic structure of antiferromagnetic DyVO4

The magnetic and crystallographic structure of DyVO4 has been determined by neutron diffraction on a powdered sample. The two observed lambda -type anomalies in the specific heat at 13.8 and 3.0 K are explained by a quadrupole ordering followed by an antiferromagnetic transition. At 3.0 K DyVO4 undergoes a transition to a collinear antiferromagnetically ordered state with the moments parallel to the b axis. The magnetic moment is 9/0 mu B at 1.85 K. The nuclear scattering does not allow for a crystallographic phase transition, either at 13.8 K or at 3.0 K. In order to describe the magnetic structure properly the symmetry has to be reduced, however, to orthorhombic symmetry, space group Imma-D2k28.