Journal of Materials Science

, Volume 53, Issue 19, pp 13400–13410 | Cite as

Advanced characterization technique for mechanochemically synthesized materials: neutron total scattering analysis

  • Eric C. O’Quinn
  • Jessica L. Bishop
  • Roman Sherrod
  • Joerg Neuefeind
  • Sagrario M. Montemayor
  • Antonio F. Fuentes
  • Maik Lang
Mechanochemical Synthesis


Materials that adopt the pyrochlore (A2B2O7) structure show promise for use in a variety of energy-related applications such as immobilization of actinide-rich nuclear waste and oxide fuel cells. Mechanochemical synthesis, a combination of milling and high-temperature treatment, has been successfully applied to fabricate many different pyrochlore compositions. High-resolution neutron total scattering experiments were used to gain fundamental insight into the structural details of milled Er2Ti2O7 pyrochlore and the subsequent evolution under high-temperature treatment. The milling process creates a highly disordered structure in which local atomic ordering is present that is significantly different than the observed long-range behavior. Thermal annealing leads to a complex defect recovery scheme with a gradual local rearrangement from a weberite-type atomic ordering to a pyrochlore phase independent of the sharp long-range crystallization process. Annealing of the milled sample up to 1200 °C does not reproduce the local structure of the same pyrochlore sample prepared by solid-state synthesis. This indicates that despite both samples possessing identical long-range structures, local defects induced by the milling process persist to very high temperatures. These findings provide a direct insight into the mechanochemical synthesis of pyrochlore oxides and help to better elucidate the structural properties of highly disordered complex oxides under extreme conditions from the local atomic arrangement to the macroscale.



This work was supported as part of the Materials Science of Actinides, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences, under Award No. DE-SC0001089. The research at ORNL’s Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. AFF thanks Conacyt (Mexico) for its continuous financial support on pyrochlore research at his lab. This material is based upon work supported under an Integrated University Program Graduate Fellowship (Jessica Bishop).

Compliance with ethical standards

Conflict of interest

The authors declare no conflicts of interest or competing financial interests.


  1. 1.
    Subramanian MA, Aravamudan G, Subba Rao GV (1983) Oxide pyrochlores—a review. Prog Solid State Chem 15:55–143. CrossRefGoogle Scholar
  2. 2.
    Chakoumakos BC (1984) Systematics of the pyrochlore structure type, ideal A2B2X6Y. J Solid State Chem 53:120–129. CrossRefGoogle Scholar
  3. 3.
    Payne JL, Tucker MG, Evans IR (2013) From fluorite to pyrochlore: characterisation of local and average structure of neodymium zirconate, Nd2Zr2O7. J Solid State Chem 205:29–34. CrossRefGoogle Scholar
  4. 4.
    Perriot R, Uberuaga BP (2015) Structural versus intrinsic carriers: contrasting effects of cation chemistry and disorder on ionic conductivity in pyrochlores. J Mater Chem A 3:11554–11565. CrossRefGoogle Scholar
  5. 5.
    Schelling PK, Phillpot SR, Grimes RW (2004) Optimum pyrochlore compositions for low thermal conductivity. Philos Mag Lett 84:127–137. CrossRefGoogle Scholar
  6. 6.
    Weber WJ, Ewing RC, Catlow CRA et al (1998) Radiation effects in crystalline ceramics for the immobilization of high-level nuclear waste and plutonium. J Mater Res 13:1434–1484. CrossRefGoogle Scholar
  7. 7.
    Rushton M, Grimes RW, Stanek C, Owens S (2004) Predicted pyrochlore to fluorite disorder temperature for A2Zr2O7 compositions. J Mater Res 19:1603–1604. CrossRefGoogle Scholar
  8. 8.
    Lian J, Wang L, Chen J et al (2003) The order-disorder transition in ion-irradiated pyrochlore. Acta Mater 51:1493–1502. CrossRefGoogle Scholar
  9. 9.
    Minervini L, Grimes RW, Sickafus KE (2000) Disorder in pyrochlore oxides. J Am Ceram Soc 83:1873–1878. CrossRefGoogle Scholar
  10. 10.
    Shamblin J, Feygenson M, Neuefeind J et al (2016) Probing disorder in isometric pyrochlore and related complex oxides. Nat Mater 15:507–512. CrossRefGoogle Scholar
  11. 11.
    Rooksby HP, White EAD (1964) Rare-earth niobates and tantaiates of defect fluorite- and weberite-type structures. J Am Ceram Soc 47:94–96. CrossRefGoogle Scholar
  12. 12.
    Fenner RB, Gerig RE, Murray Gibson J et al (2007) The advanced photon source looks to the future. Nucl Instrum Methods Phys Res Sect A Accel Spectrom Detect Assoc Equip 582:5–10. CrossRefGoogle Scholar
  13. 13.
    Galayda JN (1996) The advanced photon source. In: IEEE pp 4–8.
  14. 14.
    Bragg W (1913) The diffraction of short electromagnetic waves by a crystal. Proc Camb Philol Soc 17:43–57. Google Scholar
  15. 15.
    Huang J, Ran G, Lin J et al (2016) Microstructural evolution of Dy2O3–TiO2 powder mixtures during ball milling and post-milled annealing. Mater (Basel) 10:19. CrossRefGoogle Scholar
  16. 16.
    Moreno KJ, Rodrigo RS, Fuentes AF (2005) Direct synthesis of A2(Ti(1 − y)Zry)2O7 (A = Gd3+, Y3+) solid solutions by ball milling constituent oxides. J Alloys Compd 390:230–235. CrossRefGoogle Scholar
  17. 17.
    Egerton RF, Li P, Malac M (2004) Radiation damage in the TEM and SEM. In: Micron. pp 399–409Google Scholar
  18. 18.
    Dove MT, Tucker MG, Keen DA (2002) Neutron total scattering method: simultaneous determination of long-range and short-range order in disordered materials. Eur J Miner 14:331–348. CrossRefGoogle Scholar
  19. 19.
    Liang L, Rinaldi R, Schober H (2009) Neutron applications in earth, energy and environmental sciences. Springer, New YorkCrossRefGoogle Scholar
  20. 20.
    Nield VM, Keen DA (2006) Diffuse neutron scattering from crystalline materials. Clarendon Press, OxfordGoogle Scholar
  21. 21.
    Welberry TR, Weber T (2016) One hundred years of diffuse scattering. Crystallogr Rev 22:2–78. CrossRefGoogle Scholar
  22. 22.
    Mason TE, Abernathy D, Anderson I et al (2006) The spallation neutron source in Oak Ridge: a powerful tool for materials research. Phys B Condens Matter 385–386:955–960. CrossRefGoogle Scholar
  23. 23.
    Šepelák V, Düvel A, Wilkening M et al (2013) Mechanochemical reactions and syntheses of oxides. Chem Soc Rev 42:7507. CrossRefGoogle Scholar
  24. 24.
    Zyryanov VV (2008) Mechanochemical synthesis of complex oxides. Russ Chem Rev 77:105–135. CrossRefGoogle Scholar
  25. 25.
    Wang W, Liang S, Bi J et al (2014) Lanthanide stannate pyrochlores Ln2Sn2O7 (Ln = Nd, Sm, Eu, Gd, Er, Yb) nanocrystals: synthesis, characterization, and photocatalytic properties. Mater Res Bull 56:86–91. CrossRefGoogle Scholar
  26. 26.
    Merkle R, Maier J (2005) On the tammann-rule. Zeitschrift fur Anorg und Allg Chemie 631:1163–1166. CrossRefGoogle Scholar
  27. 27.
    Fuentes AF, Boulahya K, MacZka M et al (2005) Synthesis of disordered pyrochlores, A2Ti2O7 (A = Y, Gd and Dy), by mechanical milling of constituent oxides. Solid State Sci 7:343–353. CrossRefGoogle Scholar
  28. 28.
    Sanjuán ML, Guglieri C, Díaz-Moreno S et al (2011) Raman and x-ray absorption spectroscopy study of the phase evolution induced by mechanical milling and thermal treatments in R2Ti2O7 pyrochlores. Phys Rev B. Google Scholar
  29. 29.
    Cepeda-Sánchez NM, Díaz-Guillén JA, Maczka M et al (2017) Mechanochemical synthesis, crystal structure and ion conduction in the Gd2Hf2−xTixO7 system. J Mater Sci. 52:11933–11946. CrossRefGoogle Scholar
  30. 30.
    Zhang FX, Manoun B, Saxena SK (2006) Pressure-induced order-disorder transitions in pyrochlore RE2Ti2O7(RE = Y, Gd). Mater Lett 60:2773–2776. CrossRefGoogle Scholar
  31. 31.
    Neuefeind J, Feygenson M, Carruth J et al (2012) The nanoscale ordered materials diffractometer NOMAD at the spallation neutron source SNS. Nucl Instrum Methods Phys Res Sect B Beam Interact Mater Atoms 287:68–75. CrossRefGoogle Scholar
  32. 32.
    Welberry TR, Butler BD (1994) Interpretation of diffuse X-ray scattering via models of disorder. J Appl Crystallogr 27:205–231. CrossRefGoogle Scholar
  33. 33.
    Egami T, Billinge SJL (2003) Underneath the Bragg peaks: structural analysis of complex materials. Pergamon, AmsterdamGoogle Scholar
  34. 34.
    Toby BH, Von Dreele RB (2013) GSAS-II: the genesis of a modern open-source all purpose crystallography software package. J Appl Crystallogr 46:544–549. CrossRefGoogle Scholar
  35. 35.
    Farrow CL, Juhas P, Liu JW et al (2007) PDFfit2 and PDFgui: computer programs for studying nanostructure in crystals. J Phys: Condens Matter 19:335219. Google Scholar
  36. 36.
    Shamblin J, Tracy CL, Palomares RI et al (2018) Similar local order in disordered fluorite and aperiodic pyrochlore structures. Acta Mater 144:60–67. CrossRefGoogle Scholar
  37. 37.
    Chung CK, Shamblin J, O’Quinn EC et al (2018) Thermodynamic and structural evolution of Dy2Ti2O7 pyrochlore after swift heavy ion irradiation. Acta Mater 145:227–234. CrossRefGoogle Scholar
  38. 38.
    Hess NJ, Begg BD, Conradson SD et al (2002) Spectroscopic investigations of the structural phase transition in Gd2(Ti1−yZry)2O7 pyrochlores. J Phys Chem B 106:4663–4677. CrossRefGoogle Scholar
  39. 39.
    Weber WJ, Wald JW, Matzke H (1986) Effects of self-radiation damage in Cm-doped Gd2Ti2O7 and CaZrTi2O7. J Nucl Mater 138:196–209. CrossRefGoogle Scholar
  40. 40.
    Park S, Lang M, Tracy CL et al (2015) Response of Gd2Ti2O7 and La2Ti2O7 to swift-heavy ion irradiation and annealing. Acta Mater 93:1–11. CrossRefGoogle Scholar
  41. 41.
    Zhang FX, Lang M, Liu Z, Ewing RC (2010) Pressure-induced disordering and anomalous lattice expansion in La2Zr2O7 pyrochlore. Phys Rev Lett. Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Eric C. O’Quinn
    • 1
  • Jessica L. Bishop
    • 1
  • Roman Sherrod
    • 1
  • Joerg Neuefeind
    • 2
  • Sagrario M. Montemayor
    • 3
  • Antonio F. Fuentes
    • 4
  • Maik Lang
    • 1
  1. 1.Department of Nuclear EngineeringUniversity of TennesseeKnoxvilleUSA
  2. 2.Chemical and Engineering Materials Division, Spallation Neutron SourceOak Ridge National LaboratoryOak RidgeUSA
  3. 3.Centro de Investigación en Química AplicadaSaltilloMexico
  4. 4.Cinvestav Unidad SaltilloRamos ArizpeMexico

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