Atomistic simulations of structure and stability of coincidence site lattice grain boundaries in CeO2

  • Susanna Vigorito (Speaker)
  • Cooke, D. (Contributor to Paper or Presentation)
  • Molinari, M. (Contributor to Paper or Presentation)

Activity: Talk or presentation typesPoster presentation

Description

A key challenge to determine the role of microstructure on the properties of materials is to identify their structures and distinguish their individual behaviours. Grain boundaries are common structural features in oxide energy materials and many are coincidence site lattice (CSL) grain boundaries, where there is a relatively well-ordered grain boundary plane. For example, the space charge effect is common in grain boundaries of fluorite structured materials, which ultimately hinders ionic conductivity through the boundary. Cerium dioxide, CeO2, is an important electrolyte in solid oxide fuel cells and a catalyst inhomogeneous and heterogeneous systems and as such the effect of grain boundaries on its properties has drawn great interest. Using atomistic simulations based on classical energy minimization, we investigated a large range of grain boundary structures in CeO2 arising from mirroring surfaces with Miller indices {hkl} where h, k, and l = 0-9. We have mapped the minima and maxima of the potential energy surface of the resulting 160 symmetry independent grain boundaries arising from the mirroring of the surfaces. We demonstrate that our search for grain boundary structures yields quantitative comparison with known experimental CSL structures. We have calculated the formation and cleavage energies for the lowest energies grain boundary configurations and identified trends between these quantities and the so-called sigma value specific to each structure.
Period7 Sep 2022
Event titleCCP5 Annual General Meeting 2022, 42th edition
Event typeConference
Conference number42
LocationHuddersfield, United Kingdom
Degree of RecognitionInternational