High field magnetization ofFePS3

Abstract

High field magnetisation measurements in pulsed fields up to 65 Tesla have been performed on FePS3, which is nominally a good example of a two-dimensional Ising-like antiferromagnet on a honeycomb lattice. Measurements with the field parallel to the moment direction confirm the presence of two first-order transitions above 35 Tesla, to M/Msat = 1/2 and M/Msat = 1, respectively, at 4 K. The measurements are in contradiction with published estimates for the magnetic exchange parameters, but the contradiction can be resolved by allowing for anisotropic exchange parameters in the Hamiltonian. The magnetisation with the field perpendicular to the moment direction is anisotropic, with no transitions observed for fields along the a axis while a cascade of first-order transitions is observed for fields above 50 Tesla along the b axis, the latter case also showing a strong degradation of the sample after repeated pulses. The results indicate a strong magneto-lattice coupling in FePS3. Temperature-dependent measurements hint at a possible tricritical point.

Evidence for biquadratic exchange in the quasi-two-dimensional antiferromagnet FePS3

“…The inclusion of the biquadratic term does not lead to a complete understanding of the magnetic dynamics of FePS 3 . The highfield magnetization measurements showed a high degree of anisotropy when the field was applied in the ab planes, being normal to the ordered moment direction, 18 which would not be observed for dynamics governed by Eq. (6).…”

“…Furthermore, FePS 3 shows strong magnetoelastic effects at high magnetic fields to the point where a sample will self-delaminate when a sufficiently high field is applied along the b direction. 18 Consequently, the magnetoelastic effect may be responsible for the large values of the biquadratic constantK found from fitting the experimental magnon dispersion.…”

“…The nearest-neighbor exchange, J 1 , is ferromagnetic, the second nearest-neighbor exchange, J 2 , is very close to zero, and the zig-zag magnetic structure for FePS 3 is stabilized by a relatively strong antiferromagnetic J 3 . 16,18 The interlayer exchange, determined from separate data measured using a three-axis spectrometer, 5 was found to be very small, J 0 ¼ À0:0073 3 ð Þ meV. Its inclusion has only a very minor effect on modeling the spin waves and it will be ignored in subsequent discussion.…”

“…1 is stabilized due to the relative strengths of the three intraplanar exchange interactions, J 1 , J 2 , and J 3 . [16][17][18] The introduction of a biquadratic term into Eq. (1) causes the exchanges between different Bravais lattices to become inequivalent, i.e., J 1,f = J 1,α and J 2,f = J 2,α .…”

Proximity‐Coupling‐Induced Significant Enhancement of Coercive Field and Curie Temperature in 2D van der Waals Heterostructures

“…It is suitable to assume that for all of the four states, the orientations of the domains in FPS are hard to flip at the magnetic field variation range of ±0.5 T, since it takes tens of tesla to flip the spin (or domain) inside AFM crystal (see Figure S5, Supporting Information). [ 37 ] For states 1 and 3, the domain walls in FGT vanishes under saturated magnetic field. While for states 2 and 4, the orientation of some of the domains in FGT are parallel to the external magnetic field, while others are fixed to the domains in FPS due to the pinning effects caused by the proximity coupling, resulting in an inflexion in MOKE signal.…”