Magnetic structure and magnon dynamics of the quasi-two-dimensional antiferromagnet FePS3

D. Lancon (1, 2) , H. C. Walker (3) , Eric Ressouche (4) , B. Ouladdiaf (1) , K. C. Rule (5) , G. J. Mcintyre (5) , T. J. Hicks (6) , H. M. Ronnow (2) , A. R. Wildes (1)

1 ILL - Institut Laue-Langevin
2 Institute of Condensed Matter Physics [Lausanne]
3 ISIS Facility
4 MDN - Magnétisme et Diffusion Neutronique
5 ANSTO - Australian Nuclear Science and Technology Organisation [Australie]
6 Monash University [Clayton]

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 k(M) = [01 1/2] 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 J(1) = 1.46, J(2) = -0.04, and J(3) = -0.96 meV. The single-ion anisotropy is large, Delta = 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.

Mots clés: polarization analysis; MnPS3

Domaines: Physique [physics]

D. Lancon, H. C. Walker, Eric Ressouche, B. Ouladdiaf, K. C. Rule, et al.. Magnetic structure and magnon dynamics of the quasi-two-dimensional antiferromagnet FePS3. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2016, 94 (21), pp.214407. ⟨10.1103/PhysRevB.94.214407⟩. ⟨cea-01849840⟩