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The oxygen migration in the apatite-type lanthanum silicate with the cation substitution

Journal Article


Abstract


  • A theoretical model is proposed to determine the effects of Si substitution with Al on the oxygen diffusion in apatite-type lanthanum silicates based on density-functional theory (DFT) calculations for La-10(SiO4)(4)(AlO4)(2)O-2. Substitution changes the stable configuration for excess oxygen from the split interstitial to a new cluster form with the original cluster. Al doping completely changes the migration mechanism from the interstitialcy one, which was proposed for the La-9.33(SiO4)(6)O-2 starting material, to a mechanism which contains an interstitial process. Nevertheless, the migration barrier is calculated to be 0.81 eV, which indicates small changes in oxygen conduction and is consistent with the observations. The present study indicates that the cation substitution on silicon site alone does not promise the improvement of the oxide ion conduction in the lanthanum silicate.

Authors


  •   Liao, Ting (external author)
  •   Sasaki, Taizo (external author)
  •   Sun, Ziqi

Publication Date


  • 2013

Citation


  • Liao, T., Sasaki, T. & Sun, Z. (2013). The oxygen migration in the apatite-type lanthanum silicate with the cation substitution. Physical Chemistry Chemical Physics, 15 (40), 17553-17559.

Scopus Eid


  • 2-s2.0-84886890884

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/950

Has Global Citation Frequency


Number Of Pages


  • 6

Start Page


  • 17553

End Page


  • 17559

Volume


  • 15

Issue


  • 40

Place Of Publication


  • United Kingdom

Abstract


  • A theoretical model is proposed to determine the effects of Si substitution with Al on the oxygen diffusion in apatite-type lanthanum silicates based on density-functional theory (DFT) calculations for La-10(SiO4)(4)(AlO4)(2)O-2. Substitution changes the stable configuration for excess oxygen from the split interstitial to a new cluster form with the original cluster. Al doping completely changes the migration mechanism from the interstitialcy one, which was proposed for the La-9.33(SiO4)(6)O-2 starting material, to a mechanism which contains an interstitial process. Nevertheless, the migration barrier is calculated to be 0.81 eV, which indicates small changes in oxygen conduction and is consistent with the observations. The present study indicates that the cation substitution on silicon site alone does not promise the improvement of the oxide ion conduction in the lanthanum silicate.

Authors


  •   Liao, Ting (external author)
  •   Sasaki, Taizo (external author)
  •   Sun, Ziqi

Publication Date


  • 2013

Citation


  • Liao, T., Sasaki, T. & Sun, Z. (2013). The oxygen migration in the apatite-type lanthanum silicate with the cation substitution. Physical Chemistry Chemical Physics, 15 (40), 17553-17559.

Scopus Eid


  • 2-s2.0-84886890884

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/950

Has Global Citation Frequency


Number Of Pages


  • 6

Start Page


  • 17553

End Page


  • 17559

Volume


  • 15

Issue


  • 40

Place Of Publication


  • United Kingdom