Abstract
Ferrimagnetic alloys are model systems for understanding the ultrafast magnetization switching in materials with antiferromagnetically coupled sublattices. Here we investigate the dynamics of the rare-earth and transition-metal sublattices in ferrimagnetic GdFeCo and TbCo dots excited by spin–orbit torques with combined temporal, spatial and elemental resolution. We observe distinct switching regimes in which the magnetizations of the two sublattices either remain synchronized throughout the reversal process or switch following different trajectories in time and space. In the latter case, we observe a transient ferromagnetic state that lasts up to 2 ns. The asynchronous switching of the two magnetizations is ascribed to the master–agent dynamics induced by the spin–orbit torques on the transition-metal and rare-earth sublattices and their weak antiferromagnetic coupling, which depends sensitively on the alloy microstructure. Larger antiferromagnetic exchange leads to faster switching and shorter recovery of the magnetization after a current pulse. Our findings provide insight into the dynamics of ferrimagnets and the design of spintronic devices with fast and uniform switching.
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Data availability
The datasets presented in this study are available from the corresponding authors upon reasonable request and in the ETH Research Collection at https://doi.org/10.3929/ethz-b-000482072.
References
Stanciu, C. D. et al. All-optical magnetic recording with circularly polarized light. Phys. Rev. Lett. 99, 047601 (2007).
Vahaplar, K. et al. Ultrafast path for optical magnetization reversal via a strongly nonequilibrium state. Phys. Rev. Lett. 103, 66–69 (2009).
Kirilyuk, A., Kimel, A. V. & Rasing, T. Laser-induced magnetization dynamics and reversal in ferrimagnetic alloys. Rep. Prog. Phys. 76, 026501 (2013).
Kimel, A. V. & Li, M. Writing magnetic memory with ultrashort light pulses. Nat. Rev. Mater. 4, 189–200 (2019).
Siddiqui, S. A., Han, J., Finley, J. T., Ross, C. A. & Liu, L. Current-induced domain wall motion in a compensated ferrimagnet. Phys. Rev. Lett. 121, 057701 (2018).
Caretta, L. et al. Fast current-driven domain walls and small skyrmions in a compensated ferrimagnet. Nat. Nanotechnol. 13, 1154–1160 (2018).
Cai, K. et al. Ultrafast and energy-efficient spin–orbit torque switching in compensated ferrimagnets. Nat. Electron. 3, 37–42 (2020).
Yang, S. H., Ryu, K. S. & Parkin, S. Domain-wall velocities of up to 750 m s–1 driven by exchange-coupling torque in synthetic antiferromagnets. Nat. Nanotechnol. 10, 221–226 (2015).
Lalieu, M. L., Lavrijsen, R. & Koopmans, B. Integrating all-optical switching with spintronics. Nat. Commun. 10, 1–6 (2019).
Ostler, T. A. et al. Crystallographically amorphous ferrimagnetic alloys: Comparing a localized atomistic spin model with experiments. Physical Review B 84, 110 (2011).
Schellekens, A. J. & Koopmans, B. Microscopic model for ultrafast magnetization dynamics of multisublattice magnets. Phys. Rev. B 87, 020407 (2013).
Atxitia, U., Barker, J., Chantrell, R. W. & Chubykalo-Fesenko, O. Controlling the polarity of the transient ferromagneticlike state in ferrimagnets. Phys. Rev. B 89, 224421 (2014).
Davies, C. et al. Pathways for single-shot all-optical switching of magnetization in ferrimagnets. Phys. Rev. Appl. 13, 024064 (2020).
Jakobs, F. et al. Unifying femtosecond and picosecond single-pulse magnetic switching in Gd-Fe-Co. Phys. Rev. B 103, 104422 (2021).
Haltz, E., Krishnia, S., Berges, L., Mougin, A. & Sampaio, J. Domain wall dynamics in antiferromagnetically coupled double-lattice systems. Phys. Rev. B 103, 014444 (2021).
Buschow, K. H. J. Intermetallic compounds of rare-earth and 3d transition metals. Rep. Prog. Phys. 40, 1179–1256 (1977).
Radu, I. et al. Transient ferromagnetic-like state mediating ultrafast reversal of antiferromagnetically coupled spins. Nature 472, 205–208 (2011).
Ostler, T. A. et al. Ultrafast heating as a sufficient stimulus for magnetization reversal in a ferrimagnet. Nat. Commun. 3, 666 (2012).
Mentink, J. H. et al. Ultrafast spin dynamics in multisublattice magnets. Phys. Rev. Lett. 108, 057202 (2012).
Graves, C. E. et al. Nanoscale spin reversal by non-local angular momentum transfer following ultrafast laser excitation in ferrimagnetic GdFeCo. Nat. Mater. 12, 293–298 (2013).
Yang, Y. et al. Ultrafast magnetization reversal by picosecond electrical pulses. Sci. Adv. https://doi.org/10.1126/sciadv.1603117 (2017).
Wilson, R. B. et al. Ultrafast magnetic switching of GdFeCo with electronic heat currents. Phys. Rev. B 95, 180409(R) (2017).
Manchon, A. et al. Current-induced spin-orbit torques in ferromagnetic and antiferromagnetic systems. Rev. Mod. Phys. 91, 035004 (2019).
Mishra, R. et al. Anomalous current-induced spin torques in ferrimagnets near compensation. Phys. Rev. Lett. 118, 167201 (2017).
Roschewsky, N., Lambert, C.-H. & Salahuddin, S. Spin-orbit torque switching of ultralarge-thickness ferrimagnetic GdFeCo. Phys. Rev. B 96, 064406 (2017).
Je, S.-G. et al. Spin-orbit torque-induced switching in ferrimagnetic alloys: experiments and modeling. Appl. Phys. Lett. 112, 062401 (2018).
Sala, G. et al. Real-time Hall-effect detection of current-induced magnetization dynamics in ferrimagnets. Nat. Commun. 12, 656 (2021).
Gomonay, O., Jungwirth, T. & Sinova, J. High antiferromagnetic domain wall velocity induced by Néel spin-orbit torques. Phys. Rev. Lett. 117, 017202 (2016).
Shiino, T. et al. Antiferromagnetic domain wall motion driven by spin-orbit torques. Phys. Rev. Lett. 117, 087203 (2016).
Miron, I. M. et al. Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection. Nature 476, 189–193 (2011).
Baumgartner, M. et al. Spatially and time-resolved magnetization dynamics driven by spin–orbit torques. Nat. Nanotechnol. 12, 980–986 (2017).
Martinez, E. et al. Universal chiral-triggered magnetization switching in confined nanodots. Sci. Rep. 5, 10156 (2015).
Martínez, E., Raposo, V. & Alejos, Ó. Current-driven domain wall dynamics in ferrimagnets: micromagnetic approach and collective coordinates model. J. Magn. Magn. Mater. 491, 165545 (2019).
Bellouard, C. et al. Negative spin-valve effect in Co65Fe35/Ag/(Co65Fe35)50Gd50 trilayers. Phys. Rev. B 53, 5082–5085 (1996).
Tanaka, H., Takayama, S. & Fujiwara, T. Electronic-structure calculations for amorphous and crystalline Gd33Fe67 alloys. Phys. Rev. B 46, 7390–7394 (1992).
Zhou, W., Seki, T., Kubota, T., Bauer, G. E. & Takanashi, K. Spin-Hall and anisotropic magnetoresistance in ferrimagnetic Co-Gd/Pt layers. Phys. Rev. Mater. 2, 094404 (2018).
Lim, Y. et al. Dephasing of transverse spin current in ferrimagnetic alloys. Phys. Rev. B 103, 24443 (2021).
Bläsing, R. et al. Exchange coupling torque in ferrimagnetic Co/Gd bilayer maximized near angular momentum compensation temperature. Nat. Commun. 9, 4984 (2018).
Chubykalo-Fesenko, O., Nowak, U., Chantrell, R. W. & Garanin, D. Dynamic approach for micromagnetics close to the Curie temperature. Phys. Rev. B 74, 094436 (2006).
Liu, T.-M. et al. Nanoscale confinement of all-optical magnetic switching in TbFeCo - competition with nanoscale heterogeneity. Nano Lett. 15, 6862–6868 (2015).
Kirk, E. et al. Anisotropy-induced spin reorientation in chemically modulated amorphous ferrimagnetic films. Phys. Rev. Mater. 4, 074403 (2020).
Li, Z. G., Smith, D. J. & Marinero, E. E. Investigations of microstructure of thin TbFeCo films by high-resolution electron microscopy. J. Appl. Phys. 69, 6590 (1991).
Krishnia, S. et al. Spin-orbit coupling in single-layer ferrimagnets: direct observation of spin-orbit torques and chiral spin textures. Phys. Rev. Appl.16, 024040 (2021).
Mimura, Y., Imamura, N., Kobayashi, T., Okada, A. & Kushiro, Y. Magnetic properties of amorphous alloy films of Fe with Gd, Tb, Dy, Ho, or Er. J. Appl. Phys. 49, 1208–1215 (1978).
Beens, M., Lalieu, M. L., Duine, R. A. & Koopmans, B. The role of intermixing in all-optical switching of synthetic-ferrimagnetic multilayers, AIP Adv. 9, 125133 (2019).
Taylor, R. C. & Gangulee, A. Magnetic properties of 3d transition meltals in the amorphous ternary alloys: Gd0.2(FexCo1−x)0.8, Gd0.2(CoxNi1−x)0.8, and Gd0.2(FexNi1−x)0.8. Phys. Rev. B 22, 1320–1326 (1980).
Park, J. et al. Unconventional magnetoresistance induced by sperimagnetism in GdFeCo. Phys. Rev. B 103, 014421 (2021).
Konar, B., Kim, J. & Jung, I.-H. Critical systematic evaluation and thermodynamic optimization of the Fe-RE system: RE = Gd, Tb, Dy, Ho, Er, Tm, Lu, and Y. J. Phase Equilibria Diffus. 38, 509–542 (2017).
Bernstein & Gueugnon, C. Aging phenomena in TbFe thin films. J. Appl. Phys. 55, 1760–1762 (1984).
Hansen, P. Chapter 4 magnetic amorphous alloys. Handb. Magn. Mater. 6, 289–452 (1991).
Vansteenkiste, A. et al. The design and verification of MuMax3. AIP Adv. 4, 107133 (2014).
Johnson, G. R. et al. Investigations of element spatial correlation in Mn-promoted Co-based Fischer-Tropsch synthesis catalysts. J. Catal. 328, 111–122 (2015).
Hirata, A. & Chen, M. Angstrom-beam electron diffraction of amorphous materials. J. Non Cryst. Solids 383, 52–58 (2014).
Acknowledgements
We thank M. Baumgartner and C. Murer for fruitful discussions and help with the STXM measurements, and F. Binda for the assistance with the measurements at the vibrating sample magnetometer. We thank R. Erni for collaborating in the analysis of the diffraction measurements. We thank C. Vockenhuber for performing Rutherford backscattering measurements on GdFeCo and TbCo. This research was supported by the Swiss National Science Foundation (grant nos 200020_200465 and PZ00P2-179944) and the Swiss Government Excellence Scholarship (ESKAS no. 2018.0056). The PolLux end station was financed by the German Ministerium für Bildung und Forschung (BMBF) through contracts 05K16WED and 05K19WE2. The work by E.M. and V.R. was supported by the Ministerio de Economía y Competitividad of the Spanish Government (project no. MAT2017-87072-C4-1-P) and by the Consejería de Educación of the Junta de Castilla y Leon (project nos SA299P18 and SA0114P20). We acknowledge the Paul Scherrer Institut, Villigen, Switzerland for provision of synchrotron radiation beamtime at beamline X07DA-PolLux of the Swiss Light Source. We also thank the Helmholtz-Zentrum Berlin for the allocation of synchrotron radiation beamtime at the UE-46 Maxymus beamline.
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P.G., G.S. and C.-H.L. planned the experiment. G.S., C.-H.L., V.K. and G.K. performed the STXM measurements with the support of S.F., M.W. and J.R.; G.S. characterized the magnetic properties of the full films and devices. E.M. and V.R. developed the micromagnetic code and performed the simulations. M.R. performed the STEM characterization and the nanobeam diffraction measurements. M.R and G.S. analysed the STEM–EDX maps. G.S. and P.G. analysed the data and wrote the manuscript with input from E.M. All authors discussed the data and commented on the manuscript.
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Nature Materials thanks Olena Gomonay, Xuepeng Qiu and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Supplementary Notes 1–13 and Figs. 1–22.
Supplementary Video 1
Dynamics of type I.
Supplementary Video 2
Dynamics of type II.
Supplementary Video 3
Dynamics of type III.
Supplementary Video 4
Simulation of the dynamics of type I.
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Sala, G., Lambert, CH., Finizio, S. et al. Asynchronous current-induced switching of rare-earth and transition-metal sublattices in ferrimagnetic alloys. Nat. Mater. 21, 640–646 (2022). https://doi.org/10.1038/s41563-022-01248-8
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DOI: https://doi.org/10.1038/s41563-022-01248-8
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