Ion dynamics in nanocrystalline materials can be quite different compared to that in materials with μ m-sized crystallites. In particular, the substitution of iso- or aliovalent ions opens pathways to systematically control ion transport properties. Here we studied the incorporation of SrF 2 into the tysonite structure of LaF 3 and its effect on F- transport. High-energy ball milling directly transforms the binary fluorides in a structurally disordered, phase pure nanocrystalline ceramic. Compared to Sr-free LaF 3, ionic conductivity could be increased by several orders of magnitude. We attribute this enhancement to the generation of lattice strain and the formation of F defect sites. In agreement with this increase, the activation energy Ea of long-range ionic transport in the solid solution La 1 - xSr xF 3 - x significantly decreases from 0.75 eV (x= 0) to 0.49 eV (x= 0.1).
|Number of pages||13|
|Journal||Journal of Materials Science|
|Publication status||Published - 1 Oct 2018|
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering