Magnetic structure of the quasi-two-dimensional antiferromagnet NiPS3

The magnetic structure of the quasi-two-dimensional antiferromagnet NiPS3 has been determined by magnetometry and a variety of neutron diffraction techniques. The experiments show that the samples must be carefully handled, as gluing influences the magnetometry measurements while preferred orientation complicates the interpretation of powder diffraction measurements. Our global set of consistent measurements show numerous departures from previously published results. We show that the compound adopts a k = [010] antiferromagnetic structure with the moment directions mostly along the a axis, and that the paramagnetic susceptibility is isotropic. The critical behavior was also investigated through the temperature dependence of the magnetic Bragg peaks below the Neel temperature.