Strong room-temperature ferromagnetism in VSe2 monolayers on van der Waals substrates

Abstract

Reduced dimensionality and interlayer coupling in van der Waals materials gives rise to fundamentally different electronic1, optical2 and many-body quantum3,4,5 properties in monolayers compared with the bulk. This layer-dependence permits the discovery of novel material properties in the monolayer regime. Ferromagnetic order in two-dimensional materials is a coveted property that would allow fundamental studies of spin behaviour in low dimensions and enable new spintronics applications6,7,8. Recent studies have shown that for the bulk-ferromagnetic layered materials CrI3 (ref. 9) and Cr2Ge2Te6 (ref. 10), ferromagnetic order is maintained down to the ultrathin limit at low temperatures. Contrary to these observations, we report the emergence of strong ferromagnetic ordering for monolayer VSe2, a material that is paramagnetic in the bulk11,12. Importantly, the ferromagnetic ordering with a large magnetic moment persists to above room temperature, making VSe2 an attractive material for van der Waals spintronics applications.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: (Sub)monolayer VSe2 films grown on HOPG or MoS2 substrates characterized by STM and UPS.
Fig. 2: Evidence for CDW transition in monolayer VSe2.
Fig. 3: Magnetic properties of VSe2 films on HOPG substrates.
Fig. 4: Magnetic properties of VSe2 films on MoS2 substrates.

References

  1. 1.

    Mak, K. F., Lee, C., Hone, J., Shan, J. & Heinz, T. F. Atomically thin MoS2: a new direct-gap semiconductor. Phys. Rev. Lett. 105, 136805 (2010).

  2. 2.

    Splendiani, A. et al. Emerging photoluminesence in monolayer MoS2. Nano Lett. 10, 1271–1275 (2010).

  3. 3.

    Xi, X. et al. Strongly enhanced charge-density-wave order in monolayer NbSe2. Nat. Nanotech. 10, 765–770 (2015).

  4. 4.

    Kolekar, S., Bonilla, M., Ma, Y., Coy Diaz, H. & Batzill, M. Tunability of charge density wave criticality and evidence of an excitonic condensate in 1T-TiSe2 monolayers. 2D Mater. 5, 015006 (2017).

  5. 5.

    Tsen, A. W. et al. Nature of the quantum metal in a two-dimensional crystalline superconductor. Nat. Phys. 12, 208–212 (2016).

  6. 6.

    McCreary, K. M., Swartz, A. G., Han, W., Fabian, J. & Kawakami, R. K. Magnetic moment formation in graphene detected by scattering of pure spin currents. Phys. Rev. Lett. 109, 186604 (2012).

  7. 7.

    Soumyanarayanan, A., Reyren, N., Fert, A. & Panagopoulos, C. Emergent phenomena induced by spin–orbit coupling at surfaces and interfaces. Nature 539, 509–517 (2016).

  8. 8.

    Tong, W.-Y., Gong, S.-J., Wan, X. & Duan, C.-G. Concepts of ferrovalley material and anomalous valley Hall effect. Nat. Commun. 7, 13612 (2016).

  9. 9.

    Huang, B. et al. Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit. Nature 546, 270–273 (2017).

  10. 10.

    Gong, C. et al. Discovery of intrinsic ferromagmetism in two-dimensional van der Waals crystals. Nature 546, 265–269 (2017).

  11. 11.

    van Bruggen, C. F. & Haas, C. Magnetic susceptibility and electrical properties of VSe2 single crystals. Solid State Commun. 20, 251–254 (1976).

  12. 12.

    Bayard, M. & Sienko, M. J. Anomalous electric and magnetic properties of vanadium diselenide. J. Solid State Chem. 19, 325–329 (1976).

  13. 13.

    Xia, F., Wang, H., Xiao, D., Dubey, M. & Ramasubramaniam, A. Two-dimensional material nanophotonics. Nat. Photon. 8, 899–907 (2014).

  14. 14.

    Yu, Y. et al. Gate-tunable phase transitions in thin flakes of 1T-TaS2. Nat. Nanotech. 10, 270–276 (2015).

  15. 15.

    Li, L. J. et al. Controlling many-body states by the electric-field effect in a two-dimensional material. Nature 529, 185–189 (2016).

  16. 16.

    Geim, A. K. & Grigorieva, I. V. Van der Waals heterostructures. Nature 499, 419–425 (2013).

  17. 17.

    Novoselov, K. S., Mishchenko, A., Carvalho, A. & Castro Neto, A. H. 2D materials and van der Waals heterostructures. Science 353, aac9439 (2016).

  18. 18.

    Gonzalez-Herrero, H. et al. Atomic-scale control of graphene magnetism by using hydrogen atoms. Science 352, 437–441 (2016).

  19. 19.

    Nair, R. R. et al. Spin-half paramagentism in graphene induced by point defects. Nat. Phys. 8, 199–202 (2012).

  20. 20.

    Avsar, A. et al. Spin–orbit proximity effect in graphene. Nat. Commun. 5, 4875 (2014).

  21. 21.

    Li, X. & Yang, J. CrXTe3 (X = Si, Ge) nanosheets: two dimensional intrinsic ferromagnetic semiconductors. J. Mater. Chem. C 2, 7071–7076 (2014).

  22. 22.

    Zhang, W.-B., Qu, Q., Zhu, P. & Lam, C. H. Robust intrinsic ferromagnetism and half semiconductivity in stable two-dimensional single-layer chromium trihalides. Mater. Chem. C 3, 12457–12468 (2015).

  23. 23.

    Lin, M.-W. et al. Ultrathin nanosheets of CrSiTe3: a semiconducting two-dimensional ferromagnetic material. J. Mater. Chem. C 4, 315–322 (2016).

  24. 24.

    Sun, Y., Zhou, Z., Wu, X. & Yang, J. Room-temperature ferromagnetism in two-dimensional Fe2Si nanosheets with enhanced spin-polarization ratio. Nano Lett. 17, 2771–2777 (2017).

  25. 25.

    Mermin, N. D. & Wagner, H. Absence of ferromagnetism or antiferromagnetism in one- or two-dimensional isotropic Heisenberg models. Phys. Rev. Lett. 17, 1133–1136 (1966).

  26. 26.

    Popov, Z. I. et al. The electronic structure and spin states of 2D graphene/VX2 (X = S, Se) heterostructures. Phys. Chem. Chem. Phys. 18, 33047–33052 (2016).

  27. 27.

    Ma, Y. et al. Evidence of the existence of magnetism in pristine VX2 monolayers (X = S, Se) and their strain-induced tunable magnetic properties. ACS Nano 6, 1695–1701 (2012).

  28. 28.

    Fuh, H. R., Yan, B., Wu, S.-C., Felser, C. & Chang, C.-R. Metal–insulator transition and the anomalous Hall effect in the layered magnetic materials VS2 and VSe2. New J. Phys. 18, 113038 (2016).

  29. 29.

    Lebègue, S., Björkman, T., Klintenberg, M., Nieminen, R. M. & Eriksson, O. Two-dimensional materials form data filtering and ab initio calculations. Phys. Rev. X 3, 031002 (2013).

  30. 30.

    Xu, K. et al. Ultrathin nanosheets of vanadium diselenide: a metallic two-dimensional material with ferromagnetic charge-density-wave behavior. Angew. Chem. Int. Ed. 52, 10477–10481 (2013).

  31. 31.

    Strocov, V. N. et al. Three-dimensional electron realm in VSe2 by soft-X-ray photoelectron spectroscopy: origin of charge-density waves. Phys. Rev. Lett. 109, 086401 (2012).

  32. 32.

    Pasztor, A., Scarfato, A., Barreteau, C., Giannini, E. & Renner, C. Dimensional crossover of the charge density wave transition in thin exfoliated VSe2. 2D Mater. 4, 041005 (2017).

  33. 33.

    Ekvall, I., Brauer, H. E., Wahlström, E. & Olin, H. Locally modified charge-density waves in Na intercalated VSe2 studied by scanning tunneling microscopy and spectroscopy. Phys. Rev. B 59, 7751–7761 (1999).

  34. 34.

    Tongay, S., Varnoosfaderani, S. S., Appleton, B. R., Wu, J. Q. & Hebard, A. F. Magnetic properties of MoS2: existence of ferromagnetism. Appl. Phys. Lett. 101, 123105 (2012).

  35. 35.

    Zhang, Z. et al. Magnetic quantum phase transition in Cr-doped Bi2(SexTe1–x)3 driven by the Stark effect. Nat. Nanotech. 12, 953–957 (2017).

Download references

Acknowledgements

This project was primarily supported by the National Science Foundation under grant DMR-1701390. V.K., R.D. and M.-H.P. also acknowledge support from the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award No. DE-FG02-07ER46438 and thank H. Srikanth for useful discussions.

Author information

Affiliations

Authors

Contributions

M.Bo., S.K., H.C.D. and Y.M. synthesized samples and characterized and analysed the samples by STM, XPS and UPS. V.K. and R.D. performed magnetic characterization. T.E. carried out the L-MOKE experiments. H.R.G. performed Raman characterization. M.-H.P. and M.Ba. directed the research and wrote the manuscript. All authors contributed to the discussion of the data and commented on the manuscript.

Corresponding author

Correspondence to Matthias Batzill.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figures 1–5

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Bonilla, M., Kolekar, S., Ma, Y. et al. Strong room-temperature ferromagnetism in VSe2 monolayers on van der Waals substrates. Nature Nanotech 13, 289–293 (2018). https://doi.org/10.1038/s41565-018-0063-9

Download citation

Further reading