Magnetic structure and magnon dynamics of the quasi-two-dimensional antiferromagnet  FePS 3

Neutron scattering from single crystals has been used to determine the magnetic structure and magnon dynamics of FePS3, an S=2 Ising-like quasi-two-dimensional antiferromagnet with a honeycomb lattice. The magnetic structure has been confirmed to have a magnetic propagation vector of kM=[0112] and the moments are collinear with the normal to the ab planes. The magnon data could be modeled using a Heisenberg Hamiltonian with a single-ion anisotropy. Magnetic interactions up to the third in-plane nearest neighbor needed to be included for a suitable fit. The best fit parameters for the in-plane exchange interactions were J1=1.46, J2=−0.04, and J3=−0.96 meV. The single-ion anisotropy is large, Δ=2.66 meV, explaining the Ising-like behavior of the magnetism in the compound. The interlayer exchange is very small, J′=−0.0073 meV, proving that FePS3 is a very good approximation to a two-dimensional magnet. ©2016 American Physical Society

Keywords

Antiferromagnetism, Magnons, Spin, Quasi particles, Monocrystals, Neutron diffraction, Anisotropy

Citation

Lançon, D., Walker, H. C., Ressouche, E., Ouladdiaf, B., Rule, K. C., McIntyre, G. J., Hicks, T. J., Rønnow, H. M., & Wildes, A. R. (2016). Magnetic structure and magnon dynamics of the quasi-two-dimensional antiferromagnet FePS 3. Physical Review B, 94(21), 214407. doi:10.1103/PhysRevB.94.214407