Dense apatite type lanthanumsilicate LSO (La9.33Si6O26) electrolyte and the Al-, Fe- andMg-doped compositions
LASO (La9.83Al1.5Si4.5O26), LFSO (La9.83Fe1.5Si4.5O26), and LMSO (La9.93Mg0.9Si5.1O26) have been prepared and investigated
in this work in terms of their oxygen self-diffusion and total conductivity. Oxygen self-diffusivities
and surface exchange coefficients and the respective activation enthalpies have been estimated and discussed.
All samples exhibit a typical Arrhenius behaviour of the surface exchange coefficients meaning that the surface
incorporation reaction is thermally activated. The doped samples exhibit higher surface concentrations as well
as higher surface exchange coefficients as compared to the undoped sample. This indicates that doping has a
direct influence to the oxygen incorporation reaction. It has been found that doping enhances the self-diffusion