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Apatite-type lanthanum silicates draw researchers. attention due to their good
performance as electrolyte materials for IT-SOFC (intermediate temperature solid oxide fuel
cells). In this paper we present Sr-doping effect on La10Si6O27 (LSO) via experimental method
and ab-initio calculation: the samples were prepared through an optimized water-based sol-gel
process. High purity, crystallinity compounds with and without Sr-doping LSO are obtained
and the resulting materials were characterized by scanning electron microscopy, X-ray
diffraction and energy-dispersive X-ray spectroscopy. Ionic conductivities and activation
energies have been measured after sintering at 1500 œC and the effect of the Sr-doping has been
investigated. The results show that the ionic conductivity is thermally activated and values lies
between 4.5 x 10-2 and 1 x 10-6 Scm-1 at 873 K as a function of the Sr-doping ratio. The ab-initio
calculation work shows the lattice parameter and band structure affected by Sr-doping, leading
to the change of macro scope properties. The calculation results of activation energies were
consistent with those obtained by experiments.
Keywords: apatite lanthanum silicates; sol-gel; ab-initio calculation; electrolyte; SOFC |
full paper (pdf, 1392 Kb)