Probing Magnetic Properties of Pt/CrPS₄ Heterostructures via X-ray Spectroscopy

Heterostructures composed of heavy metal and Van der Waals (vdW) magnets serve as platforms to investigate magnetotransport properties, enabling the electric readout of the spin-flop transition in the vdW antiferromagnet. We investigate the spin and orbital contributions to magnetism in Pt/exfoliated multilayer CrPS4 heterostructure using the synchrotron-radiation based X-ray magnetic circular dichroism (XMCD) technique measured in the total electron yield (TEY) mode. The TEY detection, with probing depth of 5-10 nm, mainly reflects the interfacial magnetic behavior near the Pt/CrPS4 boundary. A spin-flop transition appears near 0.7 T in both CrPS4 single crystal and Pt/CrPS4 heterostructures. The total Cr moment remains ~2 μB/f.u. in both systems at 14 T and 6 K. In Pt/CrPS4, the orbital moment is strongly modulated by Pt, as manifested in the enhancement from ~0.1 μB/f.u. in CrPS4 to ~0.5 μB/f.u. in Pt/CrPS4, an effect attributable to the strong spin-orbit coupling with Pt. At 25 K, total Cr moment reduces to ~1.1 μB/f.u. in both systems. The Cr orbital moment in CrPS4 remains low ~0.1 μB/f.u., whereas in Pt/CrPS4 it remains high ~0.5 μB/f.u. These findings provide qualitative evidence of robust spin-orbit coupling and orbital hybridization at Pt/CrPS4 interface, and highlight the potential of heavy metal/vdW antiferromagnet heterostructures for spin-orbitronic device applications.