MoS₂ Interface Induced Magnetism in Pd-adlayers : The Hidden Hand of Charge Transfer

Atomically thin ferromagnetic films have been a topic of interest in science and technology. In this work, on the basis of density functional theory-based calculation, including spin-orbit coupling, the details of metal-semiconductor interaction between palladium (Pd) (one and two atomic layers) and the MoS₂(001) surface are investigated. While expansively strained thin Pd layers are known to be ferromagnetic [1], we found that for one Pd layer supported on MoS2(001) the interaction with MoS2(001) suppresses the Pd ferromagnetism in spite of a large 3.17 Å Pd-Pd (in-plane) lattice constant that is induced by the MoS2 surface. For two layers of Pd supported on MoS₂(001), the magnetic moment on the Pd is partly restored resulting in a moment of 0.10 µB and 0.19 µB per Pd atom in the first and second Pd layers, respectively. Charge transfer from the MoS2(001) to the Pd is found to be responsible for magnetism of Pd layers. These results show that the Stoner criterion for magnetism can be affected by changes in the electronics band structure. These findings provide valuable insights into the tunability of magnetic properties in the Pd-MoS₂ system, suggesting that spin dependent quantum well structures are possible across some dichalcogenide-Pd heterostructures, and that electric field control of ferromagnetism in strained Pd layers is not only possible [2], but also realizable.

[1] S. Sakuragi et al, Phys. Rev. B 90, 054411 (2014)

[2] Y. Sun et al, Phys. Rev. B 81, 064413 (2010)