Magnetic interactions in the layer compounds MPX3 (M = Mn, Fe, Ni; X = S, Se)

The mpx3 phases (M = Mn, Fe, Ni; X = S, Se) with sheet structures are insulators with localized moments. They show antiferromagnetic ordering at low temperatures. From the magnetic structures determined by neutron diffraction the magnetic interactions are considered and shown to be characteristic of 2D behavior.