Jump to main content
Jump to site search

Issue 20, 2017
Previous Article Next Article

Disorder-induced transition from grain boundary to bulk dominated ionic diffusion in pyrochlores

Author affiliations

Abstract

We use molecular dynamics simulations to investigate the role of grain boundaries (GBs) on ionic diffusion in pyrochlores, as a function of the GB type, chemistry of the compound, and level of cation disorder. We observe that the presence of GBs promotes oxygen transport in ordered and low-disordered systems, as the GBs are found to have a higher concentration of mobile carriers with higher mobilities than in the bulk. Thus, in ordered samples, the ionic diffusion is 2D, localized along the grain boundary. When cation disorder is introduced, bulk carriers begin to contribute to the overall diffusion, while the GB contribution is only slightly enhanced. In highly disordered samples, the diffusive behavior at the GBs is bulk-like, and the two contributions (bulk vs. GB) can no longer be distinguished. There is thus a transition from 2D/GB dominated oxygen diffusivity to 3D/bulk dominated diffusivity versus disorder in pyrochlores. These results provide new insights into the possibility of using internal interfaces to enhance ionic conductivity in nanostructured complex oxides.

Graphical abstract: Disorder-induced transition from grain boundary to bulk dominated ionic diffusion in pyrochlores

Back to tab navigation
Please wait while Download options loads

Publication details

The article was received on 24 Feb 2017, accepted on 01 May 2017 and first published on 04 May 2017


Article type: Paper
DOI: 10.1039/C7NR01373F
Citation: Nanoscale, 2017,9, 6826-6836
  •   Request permissions

    Disorder-induced transition from grain boundary to bulk dominated ionic diffusion in pyrochlores

    R. Perriot, P. P. Dholabhai and B. P. Uberuaga, Nanoscale, 2017, 9, 6826
    DOI: 10.1039/C7NR01373F

Search articles by author