A Mössbauer study of the magnetic coupling in iron phosphorous trisulfides

The polycrystalline sample of layered compound FePS_3 has been investigated by using Mössbauer spectroscopy (12K to 300K), magnetic susceptibility measurements, x-ray diffraction and FTIR spectroscopy. The antiferromagnetic order exists below T_\rm N=120.5±1K. The Mössbauer spectra below T_\rm N indicate that the magnetization axis is perpendicular to the layer of FePS_3, and the divalent iron cations are in their high spin configurations. By fitting the hyperfine field parameters near the Néel temperature, we obtain information on the nature of magnetic interactions in the material. The results show that the magnetic coupling can be treated by the two-dimensional Ising model, and it can be interpreted on the basis of a crystal-field effect.