Ordering and the nature of the spin flop phase transition in MnPS3

Powder diffraction patterns were measured on a high quality sample of manga nese thiophosphate, MnPS3, at temperatures between 2 and 120 K and magnetic fields between 0 and 60 kOe. In zero field, the magnetic moments in MnPS3 are collinear and normal to the nb planes. On applying a sufficiently large magnetic field along the normal to the ab plane, it was found that the mom ents flop towards the b axis, in agreement with a dipole-dipole interaction model for the anisotropy. The width of this transition was found to be gre ater than 20 kOe. No evidence for critical fluctuations was seen during the spin hop phase transition.