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

  • Susanna Vigorito (Speaker)
  • Cooke, D. (Contributor to Paper or Presentation)
  • Stephen C. Parker (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 the structures and distinguish their individual behaviour. 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 in catalytic homogeneous 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 161 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.
Period5 Apr 20211 May 2021
Event titleACS Spring Meeting 2021
Event typeConference
LocationOnline
Degree of RecognitionInternational