Spin Nernst magnetoresistance for magnetization study of FePS3

The magnetization of the antiferromagnetic van der Waals material FePS3 is investigated via the spin Nernst magnetoresisance (SNMR) and spin Seebeck effect (SSE). A heater and Pt detector strips are fabricated on top of a FePS3 flake which generates a temperature gradient in FePS3 and in the Pt detector strips. We are able to detect the SNMR in Pt, which is an interface effect, and detect the SSE response, which is a bulk effect. We conclude that there are uncompensated magnetic moments in FePS3 at the interface with Pt. Via the SNMR we are able to extract the real and imaginary parts of the spin mixing conductance assuming a fully uncompensated top layer. For an in-plane thermal conductivity of 10 W/(mK) and therefore a temperature gradient of 6000 K/m in Pt we find that Gr=1.9±0.06×1013ω-1m-1 and Gi=4.8±0.02×1011ω-1m-1. In addition, the temperature gradient in FePS3 generates a magnon current in FePS3 via the SSE which can be detected by the Pt detector strips. We are able to extract a magnon diffusion length of 1.3±0.5 and 0.5±0.1μm for thermally generated magnons in FePS3 for 40 and 20 nm thicknesses, respectively.