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Direct observation of ferroelectric field effect and vacancy-controlled screening at the BiFeO3/LaxSr1xMnO3 interface

Abstract

The development of interface-based magnetoelectric devices necessitates an understanding of polarization-mediated electronic phenomena and atomistic polarization screening mechanisms. In this work, the LSMO/BFO interface is studied on a single unit-cell level through a combination of direct order parameter mapping by scanning transmission electron microscopy and electron energy-loss spectroscopy. We demonstrate an unexpected ~5% lattice expansion for regions with negative polarization charge, with a concurrent anomalous decrease of the Mn valence and change in oxygen K-edge intensity. We interpret this behaviour as direct evidence for screening by oxygen vacancies. The vacancies are predominantly accumulated at the second atomic layer of BFO, reflecting the difference of ionic conductivity between the components. This vacancy exclusion from the interface leads to the formation of a tail-to-tail domain wall. At the same time, purely electronic screening is realized for positive polarization charge, with insignificant changes in lattice and electronic properties. These results underline the non-trivial role of electrochemical phenomena in determining the functional properties of oxide interfaces. Furthermore, these behaviours suggest that vacancy dynamics and exclusion play major roles in determining interface functionality in oxide multilayers, providing clear implications for novel functionalities in potential electronic devices.

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Figure 1: Lattice spacing and polarization changes at the BFO/LSMO interface.
Figure 2: Tracing the average valence states of B-site cations at the two interfaces.
Figure 3: Oxygen content and strain at the two interfaces.
Figure 4: Landau–Ginsburg–Devonshire modelling of the data.

References

  1. Ahn, C. H. et al. Local, nonvolatile electronic writing of epitaxial Pb(Zr0.52Ti0.48)O3/SrRuO3 heterostructures. Science 276, 1100–1103 (1997).

    CAS  Google Scholar 

  2. Lee, J. H. et al. A strong ferroelectric ferromagnet created by means of spin-lattice coupling. Nature 466, 954–958 (2010).

    CAS  Article  Google Scholar 

  3. Miller, S. L. & McWhorter, P. J. Physics of the ferroelectric nonvolatile memory field-effect transistor. J. Appl. Phys. 72, 5999–6010 (1992).

    CAS  Google Scholar 

  4. Molegraaf, H. J. A. et al. Magnetoelectric effects in complex oxides with competing ground states. Adv. Mater. 21, 3470–3474 (2009).

    CAS  Google Scholar 

  5. Imada, M., Fujimori, A. & Tokura, Y. Metal-insulator transitions. Rev. Mod. Phys. 70, 1039–1263 (1998).

    CAS  Google Scholar 

  6. Bibes, M., Villegas, J. E. & Barthelemy, A. Ultrathin oxide films and interfaces for electronics and spintronics. Adv. Phys. 60, 5–84 (2011).

    CAS  Google Scholar 

  7. Cheng, G. L. et al. Sketched oxide single-electron transistor. Nature Nanotech. 6, 343–347 (2011).

    CAS  Google Scholar 

  8. Fiebig, M. Revival of the magnetoelectric effect. J. Phys. D 38, R123–R152 (2005).

    CAS  Google Scholar 

  9. Burton, J. D. & Tsymbal, E. Y. Prediction of electrically induced magnetic reconstruction at the manganite/ferroelectric interface. Phys. Rev. B 80, 174406 (2009).

    Google Scholar 

  10. Rondinelli, J. M., Stengel, M. & Spaldin, N. A. Carrier-mediated magnetoelectricity in complex oxide heterostructures. Nature Nanotech. 3, 46–50 (2008).

    CAS  Google Scholar 

  11. Yamauchi, K., Sanyal, B. & Picozzi, S. Interface effects at a half-metal/ferroelectric junction. Appl. Phys. Lett. 91, 062506 (2007).

    Google Scholar 

  12. Brivio, S. et al. Effects of Au nanoparticles on the magnetic and transport properties of La0.67Sr0.33MnO3 ultrathin layers. Phys. Rev. B 81, 094410 (2010).

    Google Scholar 

  13. Estrade, S. et al. Effect of the capping on the local Mn oxidation state in buried (001) and (110) SrTiO3/La2/3Ca1/3MnO3 interfaces. J. Appl. Phys. 110, 103903–103905 (2011).

    Google Scholar 

  14. Ferguson, J. D. et al. Epitaxial oxygen getter for a brownmillerite phase transformation in manganite films. Adv. Mater. 23, 1226–1230 (2011).

    CAS  Google Scholar 

  15. Kim, Y., Disa, A. S., Babakol, T. E. & Brock, J. D. Strain screening by mobile oxygen vacancies in SrTiO3 . Appl. Phys. Lett. 96, 251901 (2010).

    Google Scholar 

  16. Schneider, C. W. et al. The origin of oxygen in oxide thin films: Role of the substrate. Appl. Phys. Lett. 97, 192107 (2010).

    Google Scholar 

  17. Lankhorst, M. H. R., Bouwmeester, H. J. M. & Verweij, H. Use of the rigid band formalism to interpret the relationship between O chemical potential and electron concentration in La1 − xSrxCoO3 − δ . Phys. Rev. Lett. 77, 2989–2992 (1996).

    CAS  Google Scholar 

  18. Pennycook, S. J. & Nellist, P. D. Scanning Transmission Electron Microscopy: Imaging and Analysis (Springer, 2011).

    Google Scholar 

  19. Jia, C. L. et al. Atomic-scale study of electric dipoles near charged and uncharged domain walls in ferroelectric films. Nature Mater. 7, 57–61 (2008).

    CAS  Google Scholar 

  20. Chisholm, M. F., Luo, W. D., Oxley, M. P., Pantelides, S. T. & Lee, H. N. Atomic-scale compensation phenomena at polar interfaces. Phys. Rev. Lett. 105, 197602 (2010).

    Google Scholar 

  21. Chang, H. J. et al. Atomically resolved mapping of polarization and electric fields across ferroelectric/oxide interfaces by Z-contrast Imaging. Adv. Mater. 23, 2474–2479 (2011).

    CAS  Google Scholar 

  22. Jia, C. L. et al. Effect of a single dislocation in a heterostructure layer on the local polarization of a ferroelectric layer. Phys. Rev. Lett. 102, 117601 (2009).

    CAS  Google Scholar 

  23. Nelson, C. T. et al. Spontaneous vortex nanodomain arrays at ferroelectric heterointerfaces. Nano Lett. 11, 828–834 (2011).

    CAS  Article  Google Scholar 

  24. Jia, C. L., Urban, K. W., Alexe, M., Hesse, D. & Vrejoiu, I. Direct observation of continuous electric dipole rotation in flux-closure domains in ferroelectric Pb(Zr, Ti)O3 . Science 331, 1420–1423 (2011).

    CAS  Google Scholar 

  25. Gruverman, A. & Kholkin, A. Nanoscale ferroelectrics: Processing, characterization and future trends. Rep. Prog. Phys. 69, 2443–2474 (2006).

    CAS  Google Scholar 

  26. Balke, N., Bdikin, I., Kalinin, S. V. & Kholkin, A. L. Electromechanical imaging and spectroscopy of ferroelectric and piezoelectric materials: State of the art and prospects for the future. J. Am. Ceram. Soc. 92, 1629–1647 (2009).

    CAS  Google Scholar 

  27. Kalinin, S. V., Morozovska, A. N., Chen, L. Q. & Rodriguez, B. J. Local polarization dynamics in ferroelectric materials. Rep. Prog. Phys. 73, 056502 (2010).

    Google Scholar 

  28. Kim, Y-M. et al. Interplay of octahedral tilts and polar order in BiFeO3 films. Adv. Mater. 25, 2497–2504 (2013).

    CAS  Google Scholar 

  29. Yu, P. et al. Interface control of bulk ferroelectric polarization. Proc. Natl Acad. Sci. USA 109, 9710–9715 (2012).

    CAS  Google Scholar 

  30. Jia, C. L. et al. Unit-cell scale mapping of ferroelectricity and tetragonality in epitaxial ultrathin ferroelectric films. Nature Mater. 6, 64–69 (2007).

    CAS  Google Scholar 

  31. Kim, Y. M. et al. Probing oxygen vacancy concentration and homogeneity in solid-oxide fuel-cell cathode materials on the subunit-cell level. Nature Mater. 11, 888–894 (2012).

    CAS  Google Scholar 

  32. Borisevich, A. Y. et al. Suppression of octahedral tilts and associated changes in electronic properties at epitaxial oxide heterostructure interfaces. Phys. Rev. Lett. 105, 087204 (2010).

    CAS  Google Scholar 

  33. Pruneda, J. M. et al. Ferrodistortive instability at the (001) surface of half-metallic manganites. Phys. Rev. Lett. 99, 226101 (2007).

    CAS  Google Scholar 

  34. Botton, G. A., Appel, C. C., Horsewell, A. & Stobbs, W. M. Quantification of the EELS near-edge structures to study Mn doping in oxides. J. Microsc. 180, 211–216 (1995).

    CAS  Google Scholar 

  35. Cavé, L., Al, T., Loomer, D., Cogswell, S. & Weaver, L. A STEM/EELS method for mapping iron valence ratios in oxide minerals. Micron 37, 301–309 (2006).

    Google Scholar 

  36. Maurice, J. L., Imhoff, D., Contoury, J. P. & Colliex, C. Interfaces in {100} epitaxial heterostructures of perovskite oxides. Phil. Mag. 86, 2127–2146 (2006).

    CAS  Google Scholar 

  37. Oxley, M. P. & Pennycook, S. J. Image simulation for electron energy loss spectroscopy. Micron 39, 676–684 (2008).

    CAS  Google Scholar 

  38. Samet, L. et al. EELS study of interfaces in magnetoresistive LSMO/STO/LSMO tunnel junctions. Eur. Phys. J. B 34, 179–192 (2003).

    CAS  Google Scholar 

  39. Wang, Z. L., Yin, J. S. & Jiang, Y. D. EELS analysis of cation valence states and oxygen vacancies in magnetic oxides. Micron 31, 571–580 (2000).

    CAS  Google Scholar 

  40. De Jong, M. P. et al. Evidence for Mn2+ ions at surfaces of La0.7Sr0.3MnO3 thin films. Phys. Rev. B 71, 014434 (2005).

    Google Scholar 

  41. De Jong, M. P. et al. Valence electronic states related to Mn2+ at La0.7Sr0.3MnO3 surfaces characterized by resonant photoemission. Phys. Rev. B 73, 052403 (2006).

    Google Scholar 

  42. Adler, S. B. Chemical expansivity of electrochemical ceramics. J. Am. Ceram. Soc. 84, 2117–2119 (2001).

    CAS  Google Scholar 

  43. Chen, X. Y., Yu, J. S. & Adler, S. B. Thermal and chemical expansion of Sr-doped lanthanum cobalt oxide (La1 − xSrxCoO3 − δ). Chem. Mater. 17, 4537–4546 (2005).

    CAS  Google Scholar 

  44. Zeches, R. J. et al. A strain-driven morphotropic phase boundary in BiFeO3 . Science 326, 977–980 (2009).

    CAS  Google Scholar 

  45. Selbach, S. M., Tybell, T., Einarsrud, M-A. & Grande, T. Structure and properties of multiferroic oxygen hyperstoichiometric BiFe1 − xMnxO3 + δ . Chem. Mater. 21, 5176–5186 (2009).

    CAS  Google Scholar 

  46. Masó, N. & West, A. R. Electrical properties of Ca-doped BiFeO3 ceramics: From p-type semiconduction to oxide-ion conduction. Chem. Mater. 24, 2127–2132 (2012).

    Google Scholar 

  47. Yang, C. H. et al. Electric modulation of conduction in multiferroic Ca-doped BiFeO3 films. Nature Mater. 8, 485–493 (2009).

    CAS  Google Scholar 

  48. Gerra, G., Tagantsev, A. K. & Setter, N. Ferroelectricity in asymmetric metal-ferroelectric–metal heterostructures: A combined first-principles-phenomenological approach. Phys. Rev. Lett. 98, 207601 (2007).

    CAS  Google Scholar 

  49. Morozovska, A. N. et al. Finite size and intrinsic field effect on the polar-active properties of ferroelectric-semiconductor heterostructures. Phys. Rev. B 81, 205308 (2010).

    Google Scholar 

  50. Eliseev, E. A. et al. Surface effect on domain wall width in ferroelectrics. J. Appl. Phys. 106, 084102 (2009).

    Google Scholar 

  51. Sheldon, B. W. & Shenoy, V. B. Space charge induced surface stresses: Implications in ceria and other ionic solids. Phys. Rev. Lett. 106, 216104 (2011).

    Google Scholar 

  52. Eliseev, E. A., Morozovska, A. N., Svechnikov, G. S., Maksymovych, P. & Kalinin, S. V. Domain wall conduction in multiaxial ferroelectrics. Phys. Rev. B 85, 045312 (2012).

    Google Scholar 

  53. Fridkin, V. M. Ferroelectric Semiconductors (Springer, 1980).

    Google Scholar 

  54. Gureev, M. Y., Tagantsev, A. K. & Setter, N. Head-to-head and tail-to-tail 180 degrees domain walls in an isolated ferroelectric. Phys. Rev. B 83, 184104 (2011).

    Google Scholar 

  55. Vul, B. M., Guro, G. M. & Ivanchik, I. I. Encountering domains in ferroelectrics. Ferroelectrics 6, 29–31 (1973).

    CAS  Google Scholar 

  56. Riess, I. I–V relations in semiconductors with ionic motion. J. Electroceram. 17, 247–253 (2006).

    CAS  Google Scholar 

  57. Maier, J. Thermodynamics of nanosystems with a special view to charge carriers. Adv. Mater. 21, 2571–2585 (2009).

    CAS  Google Scholar 

  58. Vaz, C. A. F. et al. Origin of the magnetoelectric coupling effect in Pb(Zr0.2Ti0.8)O3/La0.8Sr0.2MnO3 multiferroic heterostructures. Phys. Rev. Lett. 104, 127202 (2010).

    CAS  Google Scholar 

  59. Chien, T. Y., Liu, J. A., Chakhalian, J., Guisinger, N. P. & Freeland, J. W. Visualizing nanoscale electronic band alignment at the La2/3Ca1/3MnO3/Nb:SrTiO3 interface. Phys. Rev. B 82, 041101 (2010).

    Google Scholar 

  60. Huang, B. C. et al. Direct observation of ferroelectric polarization-modulated band bending at oxide interfaces. Appl. Phys. Lett. 100, 122903 (2012).

    Google Scholar 

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Acknowledgements

The work is supported in part (A.Y.B., Y-M.K., S.V.K., R.M. and S.T.P.) by the Materials Science and Engineering Division, Office of Basic Energy Sciences of the US DOE and through a user project supported by Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. M.P.O. acknowledges support from DOE grant DE-FG02-09ER46554. The authors thank P. Yu (Tsinghua University, Beijing, China), Y-H. Chu (National Chiao Tung University, Hsinchu, Taiwan) and R. Ramesh (University of California Berkeley) for providing BiFeO3 films for the study. A.M. and E.E. acknowledge support via a bilateral SFFR-NSF project, namely US National Science Foundation under NSF-DMR-1210588 and State Fund of Fundamental Research of Ukraine, grant UU48/002. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the US Department of Energy under Contract No. DE-AC02-05CH11231.

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Y-M.K. conducted STEM/EELS study and data analysis; A.M. and E.E. carried out LGD modelling; M.P.O. carried out EELS profile simulations; R.M. and S.T.P. conducted first-principles calculations; S.M.S. and T.G. provided solid state chemistry reasoning; A.Y.B. and S.V.K. conceived and directed the project. All authors contributed to writing the paper.

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Correspondence to Albina Y. Borisevich.

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Kim, YM., Morozovska, A., Eliseev, E. et al. Direct observation of ferroelectric field effect and vacancy-controlled screening at the BiFeO3/LaxSr1xMnO3 interface. Nature Mater 13, 1019–1025 (2014). https://doi.org/10.1038/nmat4058

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