Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Enhanced superconductivity and ferroelectric quantum criticality in plastically deformed strontium titanate

Abstract

The properties of quantum materials are commonly tuned using experimental variables such as pressure, magnetic field and doping. Here we explore a different approach using irreversible, plastic deformation of single crystals. We show that compressive plastic deformation induces low-dimensional superconductivity well above the superconducting transition temperature (Tc) of undeformed SrTiO3, with evidence of possible superconducting correlations at temperatures two orders of magnitude above the bulk Tc. The enhanced superconductivity is correlated with the appearance of self-organized dislocation structures, as revealed by diffuse neutron and X-ray scattering. We also observe deformation-induced signatures of quantum-critical ferroelectric fluctuations and inhomogeneous ferroelectric order using Raman scattering. Our results suggest that strain surrounding the self-organized dislocation structures induces local ferroelectricity and quantum-critical dynamics that strongly influence Tc, consistent with a theory of superconductivity enhanced by soft polar fluctuations. Our results demonstrate the potential of plastic deformation and dislocation engineering for the manipulation of electronic properties of quantum materials.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Structure of plastically deformed SrTiO3.
Fig. 2: Local structure of deformed SrTiO3 from diffuse neutron scattering.
Fig. 3: Inversion-symmetry breaking and ferroelectric fluctuations in deformed SrTiO3.
Fig. 4: Low-temperature superconducting properties of plastically deformed SrTiO3.
Fig. 5: Evidence for high-temperature superconducting correlations in plastically deformed SrTiO3.
Fig. 6: Local Tc enhancement due to ferroelectric fluctuations enhanced by dislocation-induced strain.

Similar content being viewed by others

Data availability

All data and materials are available from the corresponding authors upon request.

Code availability

All computer codes used to generate the results presented in the paper are available from the corresponding authors upon request.

References

  1. Pfeiffer, E. R. & Schooley, J. F. Effect of stress on the superconductive transition temperature of strontium titanate. Phys. Rev. Lett. 19, 783–785 (1967).

    Article  CAS  Google Scholar 

  2. Chu, J.-H. et al. In-plane resistivity anisotropy in an underdoped iron arsenide superconductor. Science 329, 824–826 (2010).

    Article  CAS  Google Scholar 

  3. Steppke, A. et al. Strong peak in Tc of Sr2RuO4 under uniaxial pressure. Science 335, eaaf9398 (2017).

    Article  Google Scholar 

  4. Herrera, C. et al. Strain-engineered interaction of quantum polar and superconducting phases. Phys. Rev. Mater. 3, 124801 (2019).

    Article  CAS  Google Scholar 

  5. Jakobsen, B. et al. Formation and subdivision of deformation structures during plastic deformation. Science 321, 889–892 (2006).

    Article  Google Scholar 

  6. Sugiyama, I. et al. Ferromagnetic dislocations in antiferromagnetic NiO. Nat. Nanotech. 8, 266–270 (2013).

    Article  CAS  Google Scholar 

  7. Shimada, T., Xu, T., Araki, Y., Wang, J. & Kitamura, T. Multiferroic dislocations in ferroelectric PbTiO3. Nano Lett. 17, 2674–2680 (2017).

    Article  CAS  Google Scholar 

  8. Kolhatkar, G. et al. Second harmonic generation investigation of symmetry breaking and flexoelectricity induced by nanoindentations in SrTiO3. Adv. Funct. Mater. 29, 1901266 (2019).

    Article  Google Scholar 

  9. Willa, R., Hecker, M., Fernandes, R. M. & Schmalian, J. Inhomogeneous time-reversal symmetry breaking in Sr2RuO4. Phys. Rev. B 104, 024511 (2021).

    Article  CAS  Google Scholar 

  10. Masuda, K., Lich, L. V., Shimada, T. & Kitamura, T. Periodically-arrayed ferroelectric nanostructures induced by dislocation structures in strontium titanate. Phys. Chem. Chem. Phys. 21, 22756–22762 (2019).

    Article  CAS  Google Scholar 

  11. Schooley, J. F., Hosler, W. R. & Cohen, M. L. Superconductivity in semiconducting SrTiO3. Phys. Rev. Lett. 12, 474–475 (1964).

    Article  CAS  Google Scholar 

  12. Collignon, C., Lin, X., Rischau, C. W., Fauqué, B. & Behnia, K. Metallicity and superconductivity in doped strontium titanate. Annu. Rev. Cond. Matt. Phys. 10, 25–44 (2019).

    Article  CAS  Google Scholar 

  13. Gastiasoro, M. N., Ruhman, J. & Fernandes, R. Superconductivity in dilute SrTiO3: a review. Ann. Phys. 417, 168107 (2020).

    Article  CAS  Google Scholar 

  14. Swartz, A. G. et al. Polaronic behaviour in a weak-coupling superconductor. Proc. Natl Acad. Sci. USA 115, 1475–1480 (2018).

    Article  CAS  Google Scholar 

  15. Cava, R. J. Oxide superconductors. J. Am. Ceram. Soc. 83, 5–28 (2000).

    Article  CAS  Google Scholar 

  16. Gumbsch, P., Taeri-Baghbadrani, S., Brunner, D., Sigle, W. & Rühle, M. Plasticity and inverse brittle-to-ductile transition in strontium titanate. Phys. Rev. Lett. 87, 085505 (2001).

    Article  CAS  Google Scholar 

  17. Hirel, P., Carrez, P. & Cordier, P. From glissile to sessile: effect of temperature on <110> dislocations in perovskite materials. Scr. Mater. 120, 67–70 (2016).

    Article  CAS  Google Scholar 

  18. Gay, P. & Honeycombe, R. W. K. X-ray asterisms from deformed crystals. Proc. Phys. Soc. A 64, 844–845 (1951).

    Article  Google Scholar 

  19. Lewis, D. X-ray microbeam study of deformation bands in aluminium. Br. J. Appl. Phys. 11, 162–164 (1960).

    Article  CAS  Google Scholar 

  20. Barabash, R. I. & Klimanek, P. X-ray scattering by crystals with local lattice rotation fields. J. Appl. Crystallogr. 32, 1050–1059 (1999).

    Article  CAS  Google Scholar 

  21. Cowley, R. A. The phase transition of strontium titanate. Philos. Trans. R. Soc. Lond. A 354, 2799–2814 (1996).

    Article  CAS  Google Scholar 

  22. Burke, W. J. & Pressley, R. J. Stress induced ferroelectricity in SrTiO3. Solid State Commun. 9, 191 (1971).

    Article  CAS  Google Scholar 

  23. Coak, M. J., Haines, C. R. S., Liu, C., Guzmán-Verri, G. G. & Saxena, S. S. Pressure dependence of ferroelectric quantum critical fluctuations. Phys. Rev. B 100, 214111 (2019).

    Article  CAS  Google Scholar 

  24. Gao, P. et al. Atomic-scale measurement of flexoelectric polarization at SrTiO3 dislocations. Phys. Rev. Lett. 120, 267601 (2018).

    Article  CAS  Google Scholar 

  25. Gallais, Y. et al. Observation of incipient charge nematicity in Ba(Fe1−xCox)2As2. Phys. Rev. Lett. 111, 267001 (2013).

    Article  CAS  Google Scholar 

  26. Van Mechelen, J. L. M. et al. Electron–phonon interaction and charge carrier mass enhancement in SrTiO3. Phys. Rev. Lett. 100, 226403 (2008).

    Article  Google Scholar 

  27. Lin, X. et al. Critical doping for onset of two-band superconductivity in SrTiO3−δ. Phys. Rev. Lett. 112, 207002 (2014).

    Article  Google Scholar 

  28. Ayino, Y., Yue, J., Wang, T., Jalan, B. & Pribiag, V. S. Evidence for multi-band superconductivity above the Pauli limit in NdxSr1−xTiO3. Preprint at https://arxiv.org/abs/1812.02875 (2018).

  29. Liu, C. et al. Two-dimensional superconductivity and anisotropic transport at KTaO3 (111) interfaces. Science 371, 716–721 (2021).

    Article  CAS  Google Scholar 

  30. Vagli, R., Attanasio, C., Maritato, L. & Ruosi, A. Explanation of the resistance-peak anomaly in nonhomogeneous superconductors. Phys. Rev. B 47, 15302–15303 (1993).

    Article  Google Scholar 

  31. Lin, X., Fauqué, B. & Behnia, K. Scalable T2 resistivity in a small single-component Fermi surface. Science 349, 945–948 (2015).

    Article  CAS  Google Scholar 

  32. Spinelli, A., Torija, M. A., Liu, C., Jan, C. & Leighton, C. Electronic transport in doped SrTiO3: conduction mechanisms and potential applications. Phys. Rev. B 81, 155110 (2010).

    Article  Google Scholar 

  33. Coey, J. M. D., Venkatesan, M. & Stamenov, P. J. Surface magnetism of strontium titanate. J. Phys. Condens. Matter 28, 485001 (2016).

    Article  CAS  Google Scholar 

  34. Aird, A. & Salje, E. K. H. Sheet superconductivity in twin walls: experimental evidence of WO3−x. J. Phys. Condens. Matter 10, L377–L380 (1998).

    Article  CAS  Google Scholar 

  35. Lin, Y.-H., Chen, Y. & Goldman, A. M. Indications of superconductivity at somewhat elevated temperatures in strontium titanate subjected to high electric fields. Phys. Rev. B 82, 172507 (2010).

    Article  Google Scholar 

  36. Uwe, H. & Sakudo, T. Stress-induced ferroelectricity and soft phonon modes in SrTiO3. Phys. Rev. B 13, 271–286 (1976).

    Article  CAS  Google Scholar 

  37. Rowley, S. et al. Superconductivity in the vicinity of a ferroelectric quantum phase transition. Preprint at https://arxiv.org/abs/1801.08121 (2018).

  38. Edge, J. M., Kedem, Y., Aschauer, U., Spaldin, N. A. & Balatsky, A. V. Quantum critical origin of the superconducting dome in SrTiO3. Phys. Rev. Lett. 115, 247002 (2015).

    Article  Google Scholar 

  39. Kozii, V., Bi, Z. & Ruhman, J. Superconductivity near a ferroelectric quantum critical point in ultralow-density Dirac materials. Phys. Rev. X 9, 031046 (2019).

    CAS  Google Scholar 

  40. Gastiasoro, M. N., Trevisan, T. V. & Fernandes, R. M. Anisotropic superconductivity mediated by ferroelectric fluctuations in cubic systems with spin–orbit coupling. Phys. Rev. B 101, 174501 (2020).

    Article  CAS  Google Scholar 

  41. van der Marel, D., Barantani, F. & Rischau, C. W. Possible mechanism for superconductivity in doped SrTiO3. Phys. Rev. Res. 1, 013003 (2019).

    Article  Google Scholar 

  42. Ahadi, K. et al. Enhancing superconductivity in SrTiO3 films with strain. Sci. Adv. 5, eaaw0120 (2019).

    Article  CAS  Google Scholar 

  43. Dunnett, K., Narayan, A., Spaldin, N. A. & Balatsky, A. V. Strain and ferroelectric soft mode induced superconductivity in strontium titanate. Phys. Rev. B 97, 144506 (2018).

    Article  CAS  Google Scholar 

  44. Pelc, D., Anderson, Z., Yu, B., Leighton, C. & Greven, M. Universal superconducting precursor in three classes of unconventional superconductors. Nat. Commun. 10, 2729 (2019).

    Article  CAS  Google Scholar 

  45. Pai, Y.-Y. et al. One-dimensional nature of superconductivity at the LaAlO3/SrTiO3 interface. Phys. Rev. Lett. 120, 147001 (2018).

    Article  CAS  Google Scholar 

  46. McCalla, E., Gastiasoro, M. N., Cassuto, G., Fernandes, R. M. & Leighton, C. Low-temperature specific heat of doped SrTiO3: doping dependence of the effective mass and Kadowaki–Woods scaling violation. Phys. Rev. Mater. 3, 022001(R) (2019).

    Article  Google Scholar 

  47. Jiang, M. P. et al. The origin of incipient ferroelectricity in lead telluride. Nat. Commun. 7, 12291 (2016).

    Article  CAS  Google Scholar 

  48. Aktas, O., Crossley, S., Carpenter, M. A. & Salje, E. K. H. Polar correlations and defect-induced ferroelectricity in cryogenic KTaO3. Phys. Rev. B 90, 165309 (2014).

    Article  Google Scholar 

  49. Sleight, A. W. Bismuthates: BaBiO3 and related superconducting phases. Phys. C. 514, 152–165 (2015).

    Article  CAS  Google Scholar 

  50. Schilling, J. S., in Handbook of High-temperature Superconductivity (eds Schrieffer, J. R. & Brooks, J. S.) 427–457 (Springer, 2007).

  51. Ye, F., Liu, Y., Whitfield, R., Osborn, R. & Rosenkranz, S. Implementation of cross correlation for energy discrimination on the time-of-flight spectrometer CORELLI. J. Appl. Crystallogr. 51, 315–322 (2018).

    Article  CAS  Google Scholar 

  52. Michels-Clark, T. M., Savici, A. T., Lynch, V. E., Wang, X. & Hoffmann, C. M. Expanding Lorentz and spectrum corrections to large volumes of reciprocal space for single-crystal time-of-flight neutron diffraction. J. Appl. Crystallogr. 49, 497–506 (2016).

    Article  CAS  Google Scholar 

  53. Krogstad, M. J. et al. Reciprocal space imaging of ionic correlations in intercalation compounds. Nat. Mater. 19, 63–68 (2020).

    Article  CAS  Google Scholar 

  54. Drobac, Đ., Marohnić, Ž., Živković, I. & Prester, M. The role of lock-in phase setting in ac susceptibility measurements. Rev. Sci. Instrum. 84, 054708 (2013).

    Article  CAS  Google Scholar 

  55. Landau, L. D. & Lifshitz, E. M. Theory of Elasticity (Butterworth-Heinemann, 1986).

    Google Scholar 

Download references

Acknowledgements

We thank L.J. Thompson and Z. Jiang for help with sample preparation, S.L. Griffitt and A. Najev for assistance with the design and manufacturing of polishing rigs, C.N. Irfan Habeeb for help with figures, D. Robinson and S. Rosenkranz for assistance with X-ray scattering experiments, and B.I. Shklovskii, Y. Ayino, V. Pribiag, B. Kalisky and J. Ruhman for discussions and comments. The work at the University of Minnesota was funded by the US Department of Energy through the University of Minnesota Center for Quantum Materials, under grant number DE-SC-0016371. The work at Argonne was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract number DE-AC02-06CH11357. D.P. acknowledges support from the Croatian Science Foundation through grant number UIP-2020-02-9494. The work at Peking University was funded by the National Natural Science Foundation of China, under grant number 11874069. Sputtering and contacting of samples was conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure Network, award number NNCI-1542202.

Author information

Authors and Affiliations

Authors

Contributions

D.P. and M.G. conceived the research. S.H., R.J.S., D.P., B.D. and J.R. performed transport and susceptibility measurements. S.H., Z.W.A., D.P. and Y. Liu. performed neutron scattering experiments and analysed data. Z.W.A., R.J.S., D.P., M.J.K. and R.O. performed X-ray scattering experiments and analysed data. L.Y. and Y. Li. performed Raman scattering experiments. S.H., L.Y., D.P. and Y. Li. analysed Raman data. A.K. and R.M.F. performed calculations. C.L. provided and characterized samples. C.L. and D.P oversaw transport measurements by S.H., B.D. and J.R. M.L. and D.P. designed and manufactured the pressure cells. D.P., A.K. and M.G. wrote the paper, with input from all authors.

Corresponding authors

Correspondence to D. Pelc or M. Greven.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Materials thanks Benoit Fauqué 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.

Supplementary information

Supplementary Information

Supplementary Figs. 1–13, discussion and references.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Hameed, S., Pelc, D., Anderson, Z.W. et al. Enhanced superconductivity and ferroelectric quantum criticality in plastically deformed strontium titanate. Nat. Mater. 21, 54–61 (2022). https://doi.org/10.1038/s41563-021-01102-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41563-021-01102-3

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing