Applying stress to a ferroelastic material results in a nonlinear strain response as domains of different orientations mechanically switch. The ability to write, erase and move domain walls between such ferroelastic domains suggests a method for making nanoelectronics where the domain wall is the device. However, little is known about the magnetic properties of such domain walls. A fascinating model system is SrTiO3, where the ferroelastic domain walls display strain-tunable polarity and enhanced conductivity. Here, we reveal a long-range magnetic order with modulations along the ferroelastic domain walls in SrTiO3 and SrTiO3-based heterointerfaces, which manifests itself as a striped pattern in scanning superconducting quantum interference device maps of the magnetic landscape. In conducting interfaces, the magnetism is coupled to itinerant electrons with clear signatures in magnetotransport measurements. The magnetic state is also coupled dynamically to the lattice and can be reversibly tuned by applying local external forces. This study raises the possibility of designing nanoscale devices based on domain walls where strain-tunable ferroelectric, ferroelastic and ferromagnetic orders may coexist.
Subscribe to Journal
Get full journal access for 1 year
only $15.58 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request.
Haeni, J. H. et al. Room-temperature ferroelectricity in strained SrTiO3. Nature 430, 758–761 (2004).
Jalan, B., Allen, S. J., Beltz, G. E., Moetakef, P. & Stemmer, S. Enhancing the electron mobility of SrTiO3 with strain. Appl. Phys. Lett. 98, 132102 (2011).
Pai, Y.-Y., Tylan-Tyler, A., Irvin, P. & Levy, J. Physics of SrTiO3-based heterostructures and nanostructures: a review. Rep. Prog. Phys. 81, 036503 (2018).
Rimai, L. Electron paramagnetic resonance of trivalent gadolinium ions in strontium and barium titanates. Phys. Rev. 127, 702–710 (1962).
Cowley, R. A. Lattice dynamics and phase transitions of strontium titanate. Phys. Rev. 134, A981–A997 (1964).
Heidemann, A. & Wettengel, H. Die Messung der Gitterparameteränderung von SrTiO3. Z. Phys. Hadrons Nucl. 258, 429–438 (1973).
Lytle, F. W. X-ray diffractometry of low-temperature phase transformations in strontium titanate. J. Appl. Phys. 35, 2212–2215 (1964).
Kalisky, B. et al. Locally enhanced conductivity due to the tetragonal domain structure in LaAlO3/SrTiO3 heterointerfaces. Nat. Mater. 12, 1091–1095 (2013).
Honig, M. et al. Local electrostatic imaging of striped domain order in LaAlO3/SrTiO3. Nat. Mater. 12, 1112–1118 (2013).
Erlich, Z. et al. Optical study of tetragonal domains in LaAlO3/SrTiO3. J. Supercond. Nov. Magn. 28, 1017–1020 (2015).
Frenkel, Y. et al. Anisotropic transport at the LaAlO3/SrTiO3 interface explained by microscopic imaging of channel-flow over SrTiO3 domains. ACS Appl. Mater. Interfaces 8, 12514–12519 (2016).
Chang, T. S. Domain structure of SrTiO3 under uniaxial stresses. J. Appl. Phys. 43, 3591–3595 (1972).
Sidoruk, J. et al. Quantitative determination of domain distribution in SrTiO3—competing effects of applied electric field and mechanical stress. J. Phys. Condens. Matter 22, 235903 (2010).
Brinkman, A. et al. Magnetic effects at the interface between non-magnetic oxides. Nat. Mater. 6, 493–496 (2007).
Kalisky, B. et al. Critical thickness for ferromagnetism in LaAlO3/SrTiO3 heterostructures. Nat. Commun. 3, 922 (2012).
Kalisky, B. et al. Scanning probe manipulation of magnetism at the LaAlO3/SrTiO3 heterointerface. Nano Lett. 12, 4055–4059 (2012).
Bert, J. A. et al. Direct imaging of the coexistence of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface. Nat. Phys. 7, 767–771 (2011).
Li, L., Richter, C., Mannhart, J. & Ashoori, R. C. Coexistence of magnetic order and two-dimensional superconductivity at LaAlO3/SrTiO3 interfaces. Nat. Phys. 7, 762–766 (2011).
Cheng, G. et al. Electron pairing without superconductivity. Nature 521, 196–199 (2015).
Pai, Y.-Y. et al. One-dimensional nature of pairing and superconductivity at the SrTiO3/LaAlO3 interface. Phys. Rev. Lett. 120, 147001 (2018).
Pai, Y.-Y., Tylan-Tyler, A., Irvin, P. & Levy, J. LaAlO3/SrTiO3: a tale of two magnetisms. Preprint at https://arxiv.org/abs/1610.00789 (2016).
Banerjee, S., Erten, O. & Randeria, M. Ferromagnetic exchange, spin-orbit coupling and spiral magnetism at the LaAlO3/SrTiO3 interface. Nat. Phys. 9, 626–630 (2013).
Pavlenko, N., Kopp, T., Tsymbal, E. Y., Sawatzky, G. A. & Mannhart, J. Magnetic and superconducting phases at the LaAlO3/SrTiO3 interface: the role of interfacial Ti 3d electrons. Phys. Rev. B 85, 020407 (2012).
Bi, F. et al. Room-temperature electronically-controlled ferromagnetism at the LaAlO3/SrTiO3 interface. Nat. Commun. 5, 5019 (2014).
Ariando et al. Electronic phase separation at the LaAlO3/SrTiO3 interface. Nat. Commun. 2, 188 (2011).
Hu, H.-L. et al. Subtle interplay between localized magnetic moments and itinerant electrons in LaAlO3/SrTiO3 heterostructures. ACS Appl. Mater. Interfaces 8, 13630–13636 (2016).
Joshua, A., Ruhman, J., Pecker, S., Altman, E. & Ilani, S. Gate-tunable polarized phase of two-dimensional electrons at the LaAlO3/SrTiO3 interface. Proc. Natl Acad. Sci. USA 110, 9633–9638 (2013).
Seri, S., Schultz, M. & Klein, L. Interplay between sheet resistance increase and magnetotransport properties in LaAlO3/SrTiO3. Phys. Rev. B 86, 085118 (2012).
Gunkel, F. et al. Defect control of conventional and anomalous electron transport at complex oxide interfaces. Phys. Rev. X 6, 031035 (2016).
Ben Shalom, M. et al. Anisotropic magnetotransport at the SrTiO3/LaAlO3 interface. Phys. Rev. B 80, 140403 (2009).
Wang, X. et al. Magnetoresistance of two-dimensional and three-dimensional electron gas in LaAlO3/SrTiO3 heterostructures: influence of magnetic ordering, interface scattering, and dimensionality. Phys. Rev. B 84, 075312 (2011).
Salman, Z. et al. Nature of weak magnetism in SrTiO3/LaAlO3 multilayers. Phys. Rev. Lett. 109, 257207 (2012).
Lee, J.-S. et al. Titanium dxy ferromagnetism at the LaAlO3/SrTiO3 interface. Nat. Mater. 12, 703–706 (2013).
Wijnands, T. Scanning Superconducting Quantum Interference Device Microscopy: Sensitive Mapping of Magnetic Flux on Thin Films. PhD thesis, Univ. Twente (2013).
Fitzsimmons, M. R. et al. Upper limit to magnetism in LaAlO3/SrTiO3 heterostructures. Phys. Rev. Lett. 107, 217201 (2011).
Christensen, D. V. et al. Electron mobility in γ-Al2O3/SrTiO3. Phys. Rev. Appl. 9, 054004 (2018).
Neville, R. C., Hoeneisen, B. & Mead, C. A. Permittivity of strontium titanate. J. Appl. Phys. 43, 2124–2131 (1972).
Rowley, S. E. et al. Ferroelectric quantum criticality. Nat. Phys. 10, 367–372 (2014).
Scott, J. F., Salje, E. K. H. & Carpenter, M. A. Domain wall damping and elastic softening in SrTiO3: evidence for polar twin walls. Phys. Rev. Lett. 109, 187601 (2012).
Frenkel, Y. et al. Imaging and tuning polarity at SrTiO3 domain walls. Nat. Mater. 16, 1203–1208 (2017).
Joshua, A., Pecker, S., Ruhman, J., Altman, E. & Ilani, S. A universal critical density underlying the physics of electrons at the LaAlO3/SrTiO3 interface. Nat. Commun. 3, 1129 (2012).
Nagaosa, N., Sinova, J., Onoda, S., MacDonald, A. H. & Ong, N. P. Anomalous Hall effect. Rev. Mod. Phys. 82, 1539–1592 (2010).
Cao, Y. et al. Anomalous orbital structure in a spinel–perovskite interface. npj Quantum Mater. 1, 16009 (2016).
Yazdi-Rizi, M. et al. Infrared ellipsometry study of the confined electrons in a high-mobility γ-Al2O3/SrTiO3 heterostructure. Europhys. Lett. 113, 47005 (2016).
Pippard, A. B. Magnetoresistance in Metals (Cambridge Univ. Press, New York, 1989).
Coey, J. M. D., Venkatesan, M. & Stamenov, P. Surface magnetism of strontium titanate. J. Phys. Condens. Matter 28, 485001 (2016).
Chen, Y. Z. et al. A high-mobility two-dimensional electron gas at the spinel/perovskite interface of γ-Al2O3/SrTiO3. Nat. Commun. 4, 1371 (2013).
Christensen, D. V. et al. Controlling the carrier density of SrTiO3-based heterostructures with annealing. Adv. Electron. Mater. 3, 1700026 (2017).
Gunkel, F. et al. Thermodynamic ground states of complex oxide heterointerfaces. ACS Appl. Mater. Interfaces 9, 1086–1092 (2017).
Schütz, P. et al. Microscopic origin of the mobility enhancement at a spinel/perovskite oxide heterointerface revealed by photoemission spectroscopy. Phys. Rev. B 96, 161409 (2017).
We acknowledge useful discussions with R. Claessen and P. Schütz from the University of Würzburg, J. Levy from Pittsburgh University and Y. Zhang and Y. Gan from the Technical University of Denmark. In addition, we thank C. Bernhard and M. Yazdi for insight into the temperature dependence of the carrier density extracted by infrared ellipsometry. D.V.C. and N.P. were supported by the NICE project, which has received funding from the Independent Research Fund Denmark, grant no. 6111-00145B. L.K. acknowledges support by the Israel Science Foundation founded by the Israel Academy of Sciences and Humanities (533/15). Y.F. and B.K. were supported by European Research Council grant no. ERC-2014-STG-639792, Israeli Science Foundation grant no. ISF-1281/17, and the QuantERA ERA-NET Cofund in Quantum Technologies (project no. 731473). Y.W.X., Z.Y.C., Y.H. and H.Y.H. acknowledge support from the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under contract no. DE-AC02-76SF00515 (LAO/STO synthesis), and the Gordon and Betty Moore Foundation’s EPiQS Initiative through grant GBMF4415 (LAO/STO transport characterization).
The authors declare no competing interests.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Christensen, D.V., Frenkel, Y., Chen, Y.Z. et al. Strain-tunable magnetism at oxide domain walls. Nat. Phys. 15, 269–274 (2019). https://doi.org/10.1038/s41567-018-0363-x
Journal of Superconductivity and Novel Magnetism (2020)
SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging
Physical Review Applied (2020)
Applied Physics Letters (2020)
Science Advances (2020)