Variability and origins of grain boundary electric potential detected by electron holography and atom-probe tomography
Source abstract
Abstract
A number of grain boundary phenomena in ionic materials, in particular, anomalous (either depressed or enhanced) charge transport, have been attributed to space charge effects. Developing effective strategies to manipulate transport behaviour requires deep knowledge of the origins of the interfacial charge, as well as its variability within a polycrystalline sample with millions of unique grain boundaries. Electron holography is a powerful technique uniquely suited for studying the electric potential profile at individual grain boundaries, whereas atom-probe tomography provides access to the chemical identify of essentially every atom at individual grain boundaries. Using these two techniques, we show here that the space charge potential at grain boundaries in lightly doped, high-purity ceria can vary by almost an order of magnitude. We further find that trace impurities (<25 ppm), rather than inherent thermodynamic factors, may be the ultimate source of grain boundary charge. These insights suggest chemical tunability of grain boundary transport properties.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Advanced Materials Characterization Techniques · Electronic and Structural Properties of Oxides · Advanced materials and composites
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (49)
Show source-provided references
1. Luo, J. Interfacial engineering of solid electrolytes. J. Materiomics 1, 22–32 (2015).10.1016/j.jmat.2015.03.002 ↗
2. Zhang, T. S., Ma, J., Chan, S. H., Hing, P. & Kilner, J. A. Intermediate-temperature ionic conductivity of ceria-based solid solutions as a function of gadolinia and silica contents. Solid State Sci. 6, 565–572 (2004).10.1016/j.solidstatesciences.2004.03.013 ↗
3. Kim, S., Kim, S. K., Khodorov, S., Maier, J. & Lubomirsky, I. On determining the height of the potential barrier at grain boundaries in ion-conducting oxides. Phys. Chem. Chem. Phys. 18, 3023–3031 (2016).10.1039/C5CP06387F ↗
4. Fleig, J. & Maier, J. Finite-element calculations on the impedance of electroceramics with highly resistive grain boundaries: I, laterally inhomogeneous grain boundaries. J. Am. Ceram. Soc. 82, 3485–3493 (1999).10.1111/j.1151-2916.1999.tb02270.x ↗
5. Lei, Y. Y., Ito, Y., Browning, N. D. & Mazanec, T. J. Segregation effects at grain boundaries in fluorite-structured ceramics. J. Am. Ceram. Soc. 85, 2359–2363 (2002).10.1111/j.1151-2916.2002.tb00460.x ↗
6. Vikrant, K. S. N., Chueh, W. C. & Garcia, R. E. Charged interfaces: electrochemical and mechanical effects. Energy Environ. Sci. 11, 1993–2000 (2018).10.1039/C7EE03400H ↗
7. Maier, J. Ionic conduction in space charge regions. Prog. Solid State Chem. 23, 171–263 (1995).10.1016/0079-6786(95)00004-E ↗
8. Sato, K. Probing charge-state distribution at grain boundaries varied with dopant concentration for ceria ceramics. J. Phys. Chem. C. 121, 20407–20412 (2017).10.1021/acs.jpcc.7b07978 ↗
9. Guo, X. & Maier, J. Grain boundary blocking effect in zirconia: a Schottky barrier analysis. J. Electrochem. Soc. 148, E121–E126 (2001).10.1149/1.1348267 ↗
10. Guo, X. & Waser, R. Electrical properties of the grain boundaries of oxygen ion conductors: acceptor-doped zirconia and ceria. Prog. Mater. Sci. 51, 151–210 (2006).10.1016/j.pmatsci.2005.07.001 ↗
11. Gregori, G., Merkle, R. & Maier, J. Ion conduction and redistribution at grain boundaries in oxide systems. Prog. Mater. Sci. 89, 252–305 (2017).10.1016/j.pmatsci.2017.04.009 ↗
12. Kim, S., Fleig, J. & Maier, J. Space charge conduction: simple analytical solutions for ionic and mixed conductors and application to nanocrystalline ceria. Phys. Chem. Chem. Phys. 5, 2268–2273 (2003).10.1039/B300170A ↗
13. Rodewald, S., Fleig, J. & Maier, J. Microcontact impedance spectroscopy at single grain boundaries in Fe-doped SrTiO3 polycrystals. J. Am. Ceram. Soc. 84, 521–530 (2001).10.1111/j.1151-2916.2001.tb00693.x ↗
14. Zhang, Z. L. et al. Comparative studies of microstructure and impedance of small-angle symmetrical and asymmetrical grain boundaries in SrTiO3. Acta Materialia 53, 5007–5015 (2005).10.1016/j.actamat.2005.07.015 ↗
15. R. Diercks, D. et al. Three-dimensional quantification of composition and electrostatic potential at individual grain boundaries in doped ceria. J. Mater. Chem. A. 4, 5167–5175 (2016).10.1039/C5TA10064J ↗
16. Eguchi, K., Setoguchi, T., Inoue, T. & Arai, H. Electrical properties of ceria-based oxides and their application to solid oxide fuel cells. Solid State Ion. 52, 165–172 (1992).10.1016/0167-2738(92)90102-U ↗
17. Mogensen, M., Sammes, N. M. & Tompsett, G. A. Physical, chemical and electrochemical properties of pure and doped ceria. Solid State Ion. 129, 63–94 (2000).10.1016/S0167-2738(99)00318-5 ↗
18. Rau, W. D., Schwander, P., Baumann, F. H., Höppner, W. & Ourmazd, A. Two-dimensional mapping of the electrostatic potential in transistors by electron holography. Phys. Rev. Lett. 82, 2614–2617 (1999).10.1103/PhysRevLett.82.2614 ↗
19. Wang, Y. G. & Dravid, V. P. Determination of electrostatic characteristics at a 24°, [001] tilt grain boundary in a SrTiO3 bicrystal by electron holography. Philos. Mag. Lett. 82, 425–432 (2002).10.1080/09500830210146461 ↗
20. Ravikumar, V., Rodrigues, R. P. & Dravid, V. P. Space-charge distribution across internal interfaces in electroceramics using electron holography: II, doped grain boundaries. J. Am. Ceram. Soc. 80, 1131–1138 (1997).10.1111/j.1151-2916.1997.tb02955.x ↗
21. Ravikumar, V., Rodrigues, R. P. & Dravid, V. P. Direct imaging of spatially varying potential and charge across internal interfaces in solids. Phys. Rev. Lett. 75, 4063–4066 (1995).10.1103/PhysRevLett.75.4063 ↗
22. Guo, X., Sigle, W. & Maier, J. Blocking grain boundaries in yttria-doped and undoped ceria ceramics of high purity. J. Am. Ceram. Soc. 86, 77–87 (2003).10.1111/j.1151-2916.2003.tb03281.x ↗
23. Chueh, W. C., Yang, C. K., Garland, C. M., Lai, W. & Haile, S. M. Unusual decrease in conductivity upon hydration in acceptor doped, microcrystalline ceria. Phys. Chem. Chem. Phys. 13, 6442–6451 (2011).10.1039/c0cp02198a ↗
24. Yeh, T. C., Perry, N. H. & Mason, T. O. Nanograin composite model studies of nanocrystalline gadolinia-doped ceria. J. Am. Ceram. Soc. 94, 1073–1078 (2011).10.1111/j.1551-2916.2010.04200.x ↗
25. Haile, S. M., West, D. L. & Campbell, J. The role of microstructure and processing on the proton conducting properties of gadolinium-doped barium cerate. J. Mater. Res. 13, 1576–1595 (1998).10.1557/JMR.1998.0219 ↗
26. Tschope, A., Kilassonia, S. & Birringer, R. The grain boundary effect in heavily doped cerium oxide. Solid State Ion. 173, 57–61 (2004).10.1016/j.ssi.2004.07.052 ↗
27. Avila-Paredes, H. J., Choi, K., Chen, C. T. & Kim, S. Dopant-concentration dependence of grain-boundary conductivity in ceria: a space-charge analysis. J. Mater. Chem. 19, 4837–4842 (2009).10.1039/b904583j ↗
28. Kim, S. K., Khodorov, S., Chen, C. T., Kim, S. & Lubomirsky, I. How to interpret current-voltage relationships of blocking grain boundaries in oxygen ionic conductors. Phys. Chem. Chem. Phys. 15, 8716–8721 (2013).10.1039/c3cp00145h ↗
29. McCartney, M. R. & Gajdardziska-Josifovska, M. Absolute measurement of normalized thickness, t/λi, from off-axis electron holography. Ultramicroscopy 53, 283–289 (1994).10.1016/0304-3991(94)90040-X ↗
30. Williams, D. B. & Carter, C. B. Transmission Electron Microscopy: A Textbook for Materials Science 2nd edn (Springer, 2009).10.1007/978-0-387-76501-3 ↗
31. Shibata, N., Oba, F., Yamamoto, T. & Ikuhara, Y. Structure, energy and solute segregation behaviour of [110] symmetric tilt grain boundaries in yttria-stabilized cubic zirconia. Philos. Mag. 84, 2381–2415 (2004).10.1080/14786430410001693463 ↗
32. Bokov, A. et al. Energetic design of grain boundary networks for toughening of nanocrystalline oxides. J. Eur. Ceram. Soc. 38, 4260–4267 (2018).10.1016/j.jeurceramsoc.2018.05.007 ↗
33. Harbison, T. Anisotropic Grain Boundary Energy Function for Uranium Dioxide. BSc thesis, Brigham Young Univ. (2015).
34. Rittner, J. D. & Seidman, D. N. <110> symmetric tilt grain-boundary structures in fcc metals with low stacking-fault energies. Phys. Rev. B. 54, 6999–7015 (1996).10.1103/PhysRevB.54.6999 ↗
35. Rohrer, G. S. Grain boundary energy anisotropy: a review. J. Mater. Sci. 46, 5881–5895 (2011).10.1007/s10853-011-5677-3 ↗
36. Seidman, D. N. Three-dimensional atom-probe tomography: advances and applications. Annu. Rev. Mater. Res. 37, 127–158 (2007).10.1146/annurev.matsci.37.052506.084200 ↗
37. Aggarwal, S. & Ramesh, R. Point defect chemistry of metal oxide heterostructures. Annu. Rev. Mater. Sci. 28, 463–499 (1998).10.1146/annurev.matsci.28.1.463 ↗
38. Minervini, L., Zacate, M. O. & Grimes, R. W. Defect cluster formation in M2O3-doped CeO2. Solid State Ion. 116, 339–349 (1999).10.1016/S0167-2738(98)00359-2 ↗
39. Shannon, R. D. Revised effective ionic-radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. A 32, 751–767 (1976).10.1107/S0567739476001551 ↗
40. Ge, L., Ni, Q., Cai, G. F., Sang, T. Y. & Guo, L. C. Improving SiO2 impurity tolerance of Ce0.8Sm0.2O1.9: synergy of CaO and ZnO in scavenging grain-boundary resistive phases. J. Power Sources 324, 582–588 (2016).10.1016/j.jpowsour.2016.05.135 ↗
41. Cho, P. S. et al. Effect of CaO concentration on enhancement of grain-boundary conduction in gadolinia-doped ceria. J. Power Sources 183, 518–523 (2008).10.1016/j.jpowsour.2008.05.041 ↗
42. Kim, D. K. et al. Mitigation of highly resistive grain-boundary phase in gadolinia-doped ceria by the addition of SrO. Electrochem. Solid State Lett. 10, B91–B95 (2007).10.1149/1.2710959 ↗
43. Cho, Y. H. et al. Enhancement of grain-boundary conduction in gadolinia-doped ceria by the scavenging of highly resistive siliceous phase. Acta Materialia 55, 4807–4815 (2007).10.1016/j.actamat.2007.05.001 ↗
44. Lane, J. A., Neff, J. L. & Christie, G. M. Mitigation of the deleterious effect of silicon species on the conductivity of ceria electrolytes. Solid State Ion. 177, 1911–1915 (2006).10.1016/j.ssi.2006.02.024 ↗
45. Lee, J. H. Highly resistive intergranular phases in solid electrolytes: an overview. Monatsh. Chem. 140, 1081–1094 (2009).10.1007/s00706-009-0111-0 ↗
46. Sudarsan, P. & Moorthy, S. B. K. Synergistic effect of lithium and calcium for low temperature densification and grain boundary scavenging in samarium doped ceria electrolyte. Materials Chem. Phys. 238, https://doi.org/10.1016/j.matchemphys.2019.121900 (2019).10.1016/j.matchemphys.2019.121900 ↗
47. Thompson, A. W. Calculation of true volume grain diameter. Metallography 5, 366–369 (1972).10.1016/0026-0800(72)90018-3 ↗
48. Larson, D. J., Prosa, T. J., Ulfig, R. M., Geiser, B. P. & Kelly, T. F. Local Electrode Atom Probe Tomography: A User’s Guide (Springer, 2013).10.1007/978-1-4614-8721-0 ↗
49. Thompson, K. et al. In situ site-specific specimen preparation for atom probe tomography. Ultramicroscopy 107, 131–139 (2007).10.1016/j.ultramic.2006.06.008 ↗