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Time-resolved imaging of three-dimensional nanoscale magnetization dynamics

Nature Nanotechnology volume 15, pages 356–360 (2020)Cite this article

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Abstract

Understanding and control of the dynamic response of magnetic materials with a three-dimensional magnetization distribution is important both fundamentally and for technological applications. From a fundamental point of view, the internal magnetic structure and dynamics in bulk materials still need to be mapped1, including the dynamic properties of topological structures such as vortices2, magnetic singularities3 or skyrmion lattices4. From a technological point of view, the response of inductive materials to magnetic fields and spin-polarized currents is essential for magnetic sensors and data storage devices5. Here, we demonstrate time-resolved magnetic laminography, a pump–probe technique, which offers access to the temporal evolution of a three-dimensional magnetic microdisc with nanoscale resolution, and with a synchrotron-limited temporal resolution of 70 ps. We image the dynamic response to a 500 MHz magnetic field of the complex three-dimensional magnetization in a two-phase bulk magnet with a lateral spatial resolution of 50 nm. This is achieved with a stroboscopic measurement consisting of eight time steps evenly spaced over 2 ns. These measurements map the spatial transition between domain wall motion and the dynamics of a uniform magnetic domain that is attributed to variations in the magnetization state across the phase boundary. Our technique, which probes three-dimensional magnetic structures with temporal resolution, enables the experimental investigation of functionalities arising from dynamic phenomena in bulk and three-dimensional patterned nanomagnets6.

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Fig. 1: Time-resolved X-ray magnetic laminography.
Fig. 2: The reconstructed three-dimensional magnetic configuration of the GdCo microdisc for zero time delay between the X-ray measurements and the RF excitation field BA.
Fig. 3: Dynamic response of the three-dimensional magnetization at 500 MHz.
Fig. 4: Domain wall dynamics in the lower region of the disc containing two vortex walls.

Data availability

All data associated with this manuscript are available at https://doi.org/10.5281/zenodo.3660827.

Code availability

All analysis code and reconstruction algorithms associated with the work of this manuscript are available at https://doi.org/10.5281/zenodo.3660827.

References

  1. Templeton, T. L., Hanham, S. D. & Arrott, A. S. Helical patterns of magnetization and magnetic charge density in iron whiskers. AIP Adv. 8, 056022 (2018).

    Google Scholar 

  2. Yan, M., Hertel, R. & Schneider, C. M. Calculations of three-dimensional magnetic normal modes in mesoscopic permalloy prisms with vortex structure. Phys. Rev. B. 76, 094407 (2007).

    Google Scholar 

  3. Im, M.-Y. et al. Dynamics of the Bloch point in an asymmetric permalloy disk. Nat. Commun. 10, 593 (2019).

    Google Scholar 

  4. Milde, P. et al. Unwinding of a Skyrmion lattice by magnetic monopoles. Science 340, 1076 (2013).

    CAS  Google Scholar 

  5. Hubert, A. & Schäfer, R. Magnetic Domains: The Analysis of Magnetic Microstructures (Springer, 1998).

  6. Fernández-Pacheco, A. et al. Three-dimensional nanomagnetism. Nat. Commun. 8, 15756 (2017).

    Google Scholar 

  7. Raabe, J. et al. Quantitative analysis of magnetic excitations in landau flux-closure structures using synchrotron-radiation microscopy. Phys. Rev. Lett. 94, 217204 (2005).

    CAS  Google Scholar 

  8. Wintz, S. et al. Magnetic vortex cores as tunable spin-wave emitters. Nat. Nanotechnol. 11, 948 (2016).

    CAS  Google Scholar 

  9. Choe, S. B. et al. Vortex core-driven magnetization dynamics. Science 304, 420 (2004).

    CAS  Google Scholar 

  10. Van Waeyenberge, B. et al. Magnetic vortex core reversal by excitation with short bursts of an alternating field. Nature 444, 461–464 (2006).

    Google Scholar 

  11. Baumgartner, M. et al. Spatially and time-resolved magnetization dynamics driven by spin–orbit torques. Nat. Nanotechnol. 12, 980 (2017).

    CAS  Google Scholar 

  12. Finizio, S. et al. Dynamic imaging of the delay- and tilt-free motion of Néel domain walls in perpendicularly magnetized superlattices. Nano Lett. 19, 375–380 (2019).

    CAS  Google Scholar 

  13. Stein, F.-U. et al. Time-resolved imaging of nonlinear magnetic domain-wall dynamics in ferromagnetic nanowires. Sci. Rep. 3, 1737 (2013).

    Google Scholar 

  14. Vogel, J. et al. Direct observation of massless domain wall dynamics in nanostripes with perpendicular magnetic anisotropy. Phys. Rev. Lett. 108, 247202 (2012).

    CAS  Google Scholar 

  15. Woo, S. et al. Deterministic creation and deletion of a single magnetic skyrmion observed by direct time-resolved X-ray microscopy. Nat. Electron. 1, 288–296 (2018).

    Google Scholar 

  16. Büttner, F. et al. Dynamics and inertia of skyrmionic spin structures. Nat. Phys. 11, 225 (2015).

  17. Wartelle, A. et al. Bloch-point-mediated topological transformations of magnetic domain walls in cylindrical nanowires. Phys. Rev. B. 99, 024433 (2019).

    CAS  Google Scholar 

  18. Donnelly, C. et al. Three-dimensional magnetization structures revealed with X-ray vector nanotomography. Nature 547, 328 (2017).

    CAS  Google Scholar 

  19. Suzuki, M. et al. Three-dimensional visualization of magnetic domain structure with strong uniaxial anisotropy via scanning hard X-ray microtomography. Appl. Phys. Express 11, 036601 (2018).

    Google Scholar 

  20. Hilger, A. et al. Tensorial neutron tomography of three-dimensional magnetic vector fields in bulk materials. Nat. Commun. 9, 4023 (2018).

    CAS  Google Scholar 

  21. Kardjilov, N. et al. Three-dimensional imaging of magnetic fields with polarized neutrons. Nat. Phys. 4, 399–403 (2008).

    CAS  Google Scholar 

  22. Manke, I. et al. Three-dimensional imaging of magnetic domains. Nat. Commun. 1, 125 (2010).

    CAS  Google Scholar 

  23. Tanigaki, T. et al. Three-dimensional observation of magnetic vortex cores in stacked ferromagnetic discs. Nano Lett. 15, 1309–1314 (2015).

    CAS  Google Scholar 

  24. Streubel, R. et al. Retrieving spin textures on curved magnetic thin films with full-field soft X-ray microscopies. Nat. Commun. 6, 7612 (2015).

    Google Scholar 

  25. Blanco-Roldan, C. et al. Nanoscale imaging of buried topological defects with quantitative X-ray magnetic microscopy. Nat. Commun. 6, 8196 (2015).

    CAS  Google Scholar 

  26. Donnelly, C. et al. High-resolution hard X-ray magnetic imaging with dichroic ptychography. Phys. Rev. B. 94, 064421 (2016).

    Google Scholar 

  27. Beaurepaire, E., Bulou, H., Scheurer, F. & Jean-Paul, K. (eds) Magnetism and Synchrotron Radiation (Springer, 2010).

  28. Holler, M. et al. Three-dimensional imaging of integrated circuits with macro- to nanoscale zoom. Nat. Electron. 2, 464–470 (2019).

    Google Scholar 

  29. Donnelly, C. et al. Tomographic reconstruction of a three-dimensional magnetization vector field. New J. Phys. 20, 083009 (2018).

    Google Scholar 

  30. Kneller, E. F. & Hawig, R. The exchange-spring magnet: a new material principle for permanent magnets. IEEE Trans. Magn. 27, 3588–3560 (1991).

    CAS  Google Scholar 

  31. Ha, J. K., Hertel, R. & Kirschner, J. Micromagnetic study of magnetic configurations in submicron permalloy disks. Phys. Rev. B. 67, 224432 (2003).

    Google Scholar 

  32. Gatel, C. et al. Size-specific spin configurations in single iron nanomagnet: from flower to exotic vortices. Nano Lett. 15, 6952–6957 (2015).

    CAS  Google Scholar 

  33. Parkin, S. S. P., Hayashi, M. & Thomas, L. Magnetic domain-wall racetrack memory. Science 320, 190–194 (2008).

    CAS  Google Scholar 

  34. Allwood, D. A. et al. Magnetic domain-wall logic. Science 309, 1688–1692 (2005).

    CAS  Google Scholar 

  35. Kaka, S. et al. Mutual phase-locking of microwave spin torque nano-oscillators. Nature 437, 389–392 (2005).

    CAS  Google Scholar 

  36. Mancoff, F. B. et al. Phase-locking in double-point-contact spin-transfer devices. Nature 437, 393–395 (2005).

    CAS  Google Scholar 

  37. Odstrčil, M. et al. Towards optimized illumination for high-resolution ptychography. Opt. Express 27, 14981–14997 (2019).

    Google Scholar 

  38. Holler, M. & Raabe, J. Error motion compensating tracking interferometer for the position measurement of objects with rotational degree of freedom. Opt. Eng. 54, 054101 (2015).

    Google Scholar 

  39. Holler, M. et al. OMNY—a tomography nano cryo stage. Rev. Sci. Instrum. 89, 043706 (2018).

    CAS  Google Scholar 

  40. Guizar-Sicairos, M. et al. High-throughput ptychography using Eiger: scanning X-ray nano-imaging of extended regions. Opt. Express 22, 14859–14870 (2014).

    Google Scholar 

  41. Thibault, P. et al. High-resolution scanning x-ray diffraction microscopy. Science 321, 379–382 (2008).

    CAS  Google Scholar 

  42. Thibault, P. & Guizar-Sicairos, M. Maximum-likelihood refinement for coherent diffractive imaging. New J. Phys. 14, 063004 (2012).

    Google Scholar 

  43. Odstrčil, M. et al. Alignment methods for nanotomography with deep subpixel accuracy. Opt. Express 27, 36637–36652 (2019).

    Google Scholar 

  44. Donnelly, C. & Guizar-Sicairos, M. Magnetic tomography reconstruction algorithm v.1.0.1. (Zenodo, 2018); https://doi.org/10.5281/zenodo.1324335

  45. Attwood, D. Soft X-Rays and Extreme Ultraviolet Radiation Ch. 9 (Cambridge Univ. Press, 1999).

  46. van Heel, M. & Schatz, M. Fourier shell correlation threshold criteria. J. Struct. Biol. 151, 250–262 (2005).

    Google Scholar 

  47. Guizar-Sicairos, M., Thurman, S. T. & Fienup, J. R. Efficient subpixel image registration algorithms. Opt. Lett. 33, 156–158 (2008).

    Google Scholar 

Download references

Acknowledgements

We thank D. Marty for initial discussions about the sample fabrication and design, E. Müller for focused ion beam patterning of the sample. All data was measured at the cSAXS beamline, Swiss Light Source, Paul Scherrer Institute, Switzerland. C.D. acknowledges funding from the Leverhulme Trust (grant no. ECF-2018-016), the Isaac Newton Trust (grant no. 18-08) and the L’Oréal-UNESCO UK and Ireland Fellowship for Women In Science 2019. A.H. was funded by the European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement no. 794207 (ASIQS). S.M. acknowledges funding from the Swiss National Science Foundation under grant agreement no. 172517.

Author information

Authors and Affiliations

  1. Cavendish Laboratory, University of Cambridge, Cambridge, UK

    Claire Donnelly

  2. Paul Scherrer Institute, Villigen, Switzerland

    Claire Donnelly, Simone Finizio, Sebastian Gliga, Mirko Holler, Aleš Hrabec, Michal Odstrčil, Sina Mayr, Valerio Scagnoli, Laura J. Heyderman, Manuel Guizar-Sicairos & Jörg Raabe

  3. Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, Zurich, Switzerland

    Claire Donnelly, Sebastian Gliga, Aleš Hrabec, Sina Mayr, Valerio Scagnoli & Laura J. Heyderman

  4. SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, UK

    Sebastian Gliga

  5. Laboratory for Magnetism and Interface Physics, Department of Materials, ETH Zurich, Zurich, Switzerland

    Aleš Hrabec

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  1. Claire Donnelly
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Contributions

C.D. and S.F. conceived the study of three-dimensional magnetic dynamics with input from J.R. Project discussions involved C.D., S.F., S.G., V.S, M.H., A.H., L.J.H., M.G.-S. and J.R. The sample fabrication was planned by C.D. and S.F. and performed by C.D., A.H. and S.M. The time-resolved electronics setup was designed and implemented by S.F. and J.R. The laminography endstation was designed and built by M.H. The diamond phase plate for the production of circular polarization was implemented by V.S. The synchrotron measurements were performed by C.D., S.F., M.G.-S., M.H., V.S. and J.R. The non-magnetic laminography reconstruction code was developed by M.O., and used by C.D. with the support of M.O. The magnetic laminography reconstruction was developed and used by C.D., with the support of M.G.-S. Data analysis was conducted by C.D. with the support of M.G.-S. The time-resolved three-dimensional magnetic data was interpreted by C.D., S.F., S.G. and M.G.-S. C.D. wrote the manuscript with contributions from all authors. The clarity of the final manuscript was ensured by C.D., S.G., L.J.H. and M.G.-S.

Corresponding authors

Correspondence to Claire Donnelly, Manuel Guizar-Sicairos or Jörg Raabe.

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The authors declare no competing interests.

Additional information

Peer review information Nature Nanotechnology thanks Salvador Ferrer and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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

Extended data

Extended Data Fig. 1 The error in the direction of the reconstructed magnetization vector field(Δθm) for different laminography tilt angles is determined by numerical simulations of magnetic laminography.

The simulations show that there exists a range of angles (40°–80°) for which the 3D structure can be reconstructed with a high degree of accuracy. The accuracy of the reconstruction is determined by calculating the RMS error of the direction of the reconstructed magnetization with respect to the original structure (Δθm). The tilt angle used in the experiment presented in this manuscript is 61°, which lies comfortably within this range and is indicated with an arrow.

Extended Data Fig. 2 Determination of the spatial resolution of the reconstructed magnetization by calculating the edge sharpness across the core of a vortex domain wall.

Line profiles of (a) the mx and (b) the mz components of the magnetization across the vortex domain wall. The 25%-75% edge sharpness is found to be on average 50 nm, indicating a half-period spatial resolution of 50 nm. c, The line along which the profile is measured is drawn in blue.

Extended Data Fig. 3 Determination of the spatial resolution of the reconstructed magnetization by calculating the Fourier Shell Correlation.

Fourier Shell Correlation of (a) the mx, (b) the my and (c) the mz components of the magnetization. An estimate of the spatial resolution is obtained using the 1/2 bit threshold36 (red dashed line) and is found to be 184 nm, 360 nm and 180 nm for the mx, my and mz components of the magnetization, respectively.

Extended Data Fig. 4 Schematic showing the positions within the sample for which the magnetization and dynamics are shown.

The heights at which the magnetization and dynamics are shown in Figs. 2a–d and 3a–d are indicated by semi-transparent discs, superimposed on the three-dimensional rendering of the magnetization modes shown in Fig. 3e.

Extended Data Fig. 5 Comparison of the divergence and angular direction of the magnetization within a single slice, that are used for alignment purposes.

Images of a, ∇sin(θm) and b, sin(θm) of the lowest slice of the magnetization. One can see that for ∇sin(θm) in a, the signal is limited to the domain walls, whereas for sin(θm) the signal is non-zero in the majority of the structure.

Extended Data Fig. 6 Vortex domain wall displacement within the bulk of the microdisc.

Displacement of the vortex domain walls with negative vorticity (a, blue in left-hand panel and Fig. 4) and positive vorticity (b, red in left-hand panel and Fig. 4) in the direction perpendicular to the long axis of the domain wall (indicated by grey arrows in the left-hand panel) as a function of time for different heights within the structure. The oscillatory behaviour is clearest for both vortices at a height of 46 nm and is less clear at the top. When comparing the motion of the two vortex domain walls, the oscillations appear to be consistently out of phase through the height of the sample. Scale bar is 1 μm.

Supplementary information

Supplementary Video 1

Three-dimensional static magnetic configuration shown through the bulk of the microdisc.

Supplementary Video 2

Dynamic response of the three-dimensional magnetization at 500 MHz.

Supplementary Video 3

Domain wall dynamics in the lower region of the disc containing two vortex walls.

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Donnelly, C., Finizio, S., Gliga, S. et al. Time-resolved imaging of three-dimensional nanoscale magnetization dynamics. Nat. Nanotechnol. 15, 356–360 (2020). https://doi.org/10.1038/s41565-020-0649-x

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