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Enhancement of interlayer exchange in an ultrathin two-dimensional magnet

An Author Correction to this article was published on 24 September 2019

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Abstract

Following the recent isolation of monolayer CrI3 (ref. 1), many more two-dimensional van der Waals magnetic materials have been isolated2,3,4,5,6,7,8,9,10,11,12. Their incorporation in van der Waals heterostructures offers a new platform for spintronics5,6,7,8,9, proximity magnetism13 and quantum spin liquids14. A primary question in this field is how exfoliating crystals to the few-layer limit influences their magnetism. Studies of CrI3 have shown a different magnetic ground state for ultrathin exfoliated films1,5,6 compared with the bulk, but the origin is not yet understood. Here, we use electron tunnelling through few-layer crystals of the layered antiferromagnetic insulator CrCl3 to probe its magnetic order and find a tenfold enhancement of the interlayer exchange compared with bulk crystals. Moreover, temperature- and polarization-dependent Raman spectroscopy reveals that the crystallographic phase transition of bulk crystals does not occur in exfoliated films. This results in a different low-temperature stacking order and, we hypothesize, increased interlayer exchange. Our study provides insight into the connection between stacking order and interlayer interactions in two-dimensional magnets, which may be relevant for correlating stacking faults and mechanical deformations with the magnetic ground states of other more exotic layered magnets such as RuCl3 (ref. 14).

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Fig. 1: CrCl3 stacking order and device characteristics.
Fig. 2: Magnetoresistance in CrCl3 magnetic tunnel junctions.
Fig. 3: Thickness dependence of CrCl3 magnetic tunnel junctions.
Fig. 4: Raman spectroscopy of bulk and exfoliated CrCl3.

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Data availability

The data that support the findings of this study are available at https://dataverse.harvard.edu/dataverse/crcl3.

Change history

  • 24 September 2019

    An amendment to this paper has been published and can be accessed via a link at the top of the paper.

References

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

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  3. Huang, B. et al. Electrical control of 2D magnetism in bilayer CrI3. Nat. Nanotechnol. 13, 544–548 (2018).

    Article  ADS  Google Scholar 

  4. Seyler, K. L. et al. Ligand-field helical luminescence in a 2D ferromagnetic insulator. Nat. Phys. 14, 277–281 (2018).

    Article  Google Scholar 

  5. Klein, D. R. et al. Probing magnetism in 2D van der Waals crystalline insulators via electron tunneling. Science 360, 1218–1222 (2018).

    Article  ADS  Google Scholar 

  6. Song, T. et al. Giant tunneling magnetoresistance in spin-filter van der Waals heterostructures. Science 360, 1214–1218 (2018).

    Article  ADS  Google Scholar 

  7. Wang, Z. et al. Very large tunneling magnetoresistance in layered magnetic semiconductor CrI3. Nat. Commun. 9, 2516 (2018).

    Article  ADS  Google Scholar 

  8. Kim, H. H. et al. One million percent tunnel magnetoresistance in a magnetic van der Waals heterostructure. Nano Lett. 18, 4885–4890 (2018).

    Article  ADS  Google Scholar 

  9. Ghazaryan, D. et al. Magnon-assisted tunneling in van der Waals heterostructures based on CrBr3. Nat. Electron. 1, 344–349 (2018).

    Article  Google Scholar 

  10. Kuo, C.-T. et al. Exfoliation and Raman spectroscopic fingerprint of few-layer NiPS3 van der Waals crystals. Sci. Rep. 6, 20904 (2016).

    Article  ADS  Google Scholar 

  11. Lee, J.-U. et al. Ising-type magnetic ordering in atomically thin FePS3. Nano Lett. 16, 7433–7438 (2016).

    Article  ADS  Google Scholar 

  12. Burch, K. S., Mandrus, D. & Park, J.-G. Magnetism in two-dimensional van der Waals materials. Nature 563, 47–52 (2018).

    Article  ADS  Google Scholar 

  13. Zhong, D. et al. Van der Waals engineering of ferromagnetic semiconductor heterostructures for spin and valleytronics. Sci. Adv. 3, e1603113 (2017).

    Article  ADS  Google Scholar 

  14. Banerjee, A. et al. Proximate Kitaev quantum spin liquid behaviour in a honeycomb magnet. Nat. Mater. 15, 733–740 (2016).

    Article  ADS  Google Scholar 

  15. Dillon, J. F. & Olson, C. E. Magnetization, resonance, and optical properties of the ferromagnet CrI3. J. Appl. Phys. 36, 1259–1260 (1965).

    Article  ADS  Google Scholar 

  16. Cable, J. W. et al. Neutron diffraction investigation of antiferromagnetism in CrCl3. J. Phys. Chem. Solids 19, 29–34 (1961).

    Article  ADS  Google Scholar 

  17. Narath, A. & Davis, H. L. Spin-wave analysis of the sublattice magnetization behavior of antiferromagnetic and ferromagnetic CrCl3. Phys. Rev. 137, A163–A178 (1965).

    Article  ADS  Google Scholar 

  18. Kuhlow, B. Magnetic ordering in CrCl3 at the phase transition. Phys. Status Solidi A 72, 161–168 (1982).

    Article  ADS  Google Scholar 

  19. McGuire, M. A. et al. Magnetic behavior and spin-lattice coupling in cleavable van der Waals layered CrCl3. Cryst. Phys. Rev. Mater. 1, 014001 (2017).

    Article  Google Scholar 

  20. McGuire, M. A., Dixit, H., Cooper, V. R. & Sales, B. C. Coupling of crystal structure and magnetism in the layered, ferromagnetic insulator CrI3. Chem. Mater. 27, 612–620 (2015).

    Article  Google Scholar 

  21. McGuire, M. A. Crystal and magnetic structures in layered, transition metal dihalides and trihalides. Crystals 7, 121 (2017).

    Article  Google Scholar 

  22. MacNeill, D. et al. Gigahertz frequency antiferromagnetic resonance and strong magnon–magnon coupling in the layered crystal CrCl3. Phys. Rev. Lett. 123, 047204 (2019).

    Article  ADS  Google Scholar 

  23. Jiang, S. et al. Controlling magnetism in 2D CrI3 by electrostatic doping. Nat. Nanotechnol. 13, 549–553 (2018).

    Article  ADS  Google Scholar 

  24. Thiel, L. et al. Probing magnetism in 2D materials at the nanoscale with single spin microscopy. Science 364, 973–976 (2019).

    Article  ADS  Google Scholar 

  25. Jiang, P. et al. Stacking tunable interlayer magnetism in bilayer CrI3. Phys. Rev. B 99, 144401 (2019).

    Article  ADS  Google Scholar 

  26. Soriano, D. et al. Interplay between interlayer exchange and stacking in CrI3 bilayers. Solid State Commun. 299, 113662 (2019).

    Article  Google Scholar 

  27. Sivadas, N. et al. Stacking-dependent magnetism in bilayer CrI3. Nano Lett. 18, 7658–7664 (2018).

    Article  ADS  Google Scholar 

  28. Simmons, J. G. Generalized formula for the electric tunnel effect between similar electrodes separated by a thin insulating film. J. Appl. Phys. 34, 1793–1803 (1963).

    Article  ADS  Google Scholar 

  29. Miao, G.-X., Müller, M. & Moodera, J. S. Magnetoresistance in double spin filter tunnel junctions with nonmagnetic electrodes and its unconventional bias dependence. Phys. Rev. Lett. 102, 076601 (2009).

    Article  ADS  Google Scholar 

  30. Moodera, J. S., Meservey, R. & Hao, X. Variation of the electron-spin polarization in EuSe tunnel junctions from zero to near 100% in a magnetic field. Phys. Rev. Lett. 70, 853–856 (1993).

    Article  ADS  Google Scholar 

  31. Worledge, D. C. & Geballe, T. H. Magnetoresistive double spin filter tunnel junction. J. Appl. Phys. 88, 5277–5279 (2000).

    Article  ADS  Google Scholar 

  32. Hao, X., Moodera, J. S. & Meservey, R. Spin-filter effect of ferromagnetic europium sulfide tunnel barriers. Phys. Rev. B 42, 8235–8243 (1990).

    Article  ADS  Google Scholar 

  33. Glamazda, A. et al. Relation between Kitaev magnetism and structure in α-RuCl3. Phys. Rev. B 95, 174429 (2017).

    Article  ADS  Google Scholar 

  34. Cao, H. B. et al. Low-temperature crystal and magnetic structure of α-RuCl3. Phys. Rev. B 93, 134423 (2016).

    Article  ADS  Google Scholar 

  35. Bermudez, V. M. Unit-cell vibrational spectra of chromium trichloride and chromium tribromide. Solid State Commun. 19, 693–697 (1976).

    Article  ADS  Google Scholar 

  36. Larson, D. T. & Kaxiras, E. Raman spectrum of CrI3: an ab initio study. Phys. Rev. B 98, 085406 (2018).

    Article  ADS  Google Scholar 

  37. Cao, Y. et al. Unconventional superconductivity in magic-angle graphene superlattices. Nature 556, 43–50 (2018).

    Article  ADS  Google Scholar 

  38. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953–17979 (1994).

    Article  ADS  Google Scholar 

  39. Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).

    Article  ADS  Google Scholar 

  40. Kresse, G. & Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci. 6, 15–50 (1996).

    Article  Google Scholar 

  41. Perdew, J. P. & Zunger, A. Self-interaction correction to density-functional approximations for many-electron systems. Phys. Rev. B 23, 5048–5079 (1981).

    Article  ADS  Google Scholar 

  42. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

    Article  ADS  Google Scholar 

  43. Klimeš, J., Bowler, D. R. & Michaelides, A. Chemical accuracy for the van der Waals density functional. J. Phys. Condens. Matter 22, 022201 (2010).

    Article  ADS  Google Scholar 

  44. Klimeš, J., Bowler, D. R. & Michaelides, A. Van der Waals density functionals applied to solids. Phys. Rev. B 83, 195131 (2011).

    Article  ADS  Google Scholar 

  45. Dion, M. et al. Van der Waals density functional for general geometries. Phys. Rev. Lett. 92, 246401 (2004).

    Article  ADS  Google Scholar 

  46. Dudarev, S. L. et al. Electron-energy-loss spectra and the structural stability of nickel oxide: an LSDA+U study. Phys. Rev. B 57, 1505–1509 (1998).

    Article  ADS  Google Scholar 

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Acknowledgements

This work was supported by the Center for Integrated Quantum Materials under NSF grant DMR-1231319 (D.R.K., E.K. and S.F.), the DOE Office of Science, Basic Energy Sciences under award DE-SC0018935 (D.M.), as well as the Gordon and Betty Moore Foundation’s EPiQS Initiative through grant GBMF4541 to P.J.-H.; D.R.K. acknowledges partial support by the NSF Graduate Research Fellowship Program under grant no. 1122374. R.C. acknowledges support from the Alfred P. Sloan Foundation. Q.S. is supported by the Xu Xin International Student Exchange Scholarship from Nanjing University. E.K. and S.F. are also supported by the ARO MURI award no. W911NF-14-0247. Work done at AmesLaboratory (M.X., R.A.R. and P.C.C.) was performed under contract no. DE-AC02-07CH11358. R.A.R. was supported by the Gordon and Betty Moore Foundation’s EPiQS Initiative through grant GBMF4411. The computations in this paper were run on the Odyssey cluster supported by the FAS Division of Science, Research Computing Group at Harvard University.

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D.R.K., D.M. and P.J.-H. conceived the project. D.R.K. and D.M. grew the bulk CrCl3 crystals, fabricated and measured the transport devices and analysed the data. Q.S. carried out Raman measurements under supervision of R.C.; D.T.L. and S.F. carried out symmetry analysis and DFT calculations under supervision of E.K.; M.X., R.A.R. and P.C.C. supplied the boron nitride crystals. All authors contributed to writing the manuscript.

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Correspondence to Pablo Jarillo-Herrero.

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Additional theoretical details and Supplementary Figs. 1–13.

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Klein, D.R., MacNeill, D., Song, Q. et al. Enhancement of interlayer exchange in an ultrathin two-dimensional magnet. Nat. Phys. 15, 1255–1260 (2019). https://doi.org/10.1038/s41567-019-0651-0

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