info:eu-repo/semantics/article
High Temperature Crystal Chemistry and Oxygen Permeation Properties of the Mixed Ionic–Electronic Conductors LnBaCo2O5 + δ ( Ln = Lanthanide )
Fecha
2009-06Registro en:
Kim, John H.; Mogni, Liliana Verónica; Prado, Fernando Daniel; Caneiro, Alberto; Alonso, J. A.; et al.; High Temperature Crystal Chemistry and Oxygen Permeation Properties of the Mixed Ionic–Electronic Conductors LnBaCo2O5 + δ ( Ln = Lanthanide ); Electrochemical Society; Journal of the Electrochemical Society; 156; 12; 6-2009; B1376 - B1382
0013-4651
CONICET Digital
CONICET
Autor
Kim, John H.
Mogni, Liliana Verónica
Prado, Fernando Daniel
Caneiro, Alberto
Alonso, J. A.
Manthiram, A.
Resumen
The high temperature crystal chemistry and oxygen permeation properties of the cation-ordered LnBaCo2 O5+δ perovskite oxides [lanthanide (Ln)=Pr, Nd, and Sm] have been investigated in comparison with the cation-disordered La0.5 Ba0.5 CoO3-δ perovskite. The LnBaCo2 O5+δ (Ln=Pr, Nd, and Sm) oxides exhibit a metal-insulator transition at T<200°C, as evidenced by total conductivity measurements and high temperature X-ray diffraction data and an oxygen vacancy order-disorder transition at T >350°C in air, as evidenced by an orthorhombic to tetragonal transition. At a given temperature, the oxygen permeation flux decreases from Ln=La to Nd to Sm due to the changes in crystal symmetry and lattice strain. The oxygen permeation mechanism in the Ln=Nd is bulk-diffusion-limited rather than surface-exchange-limited for membrane thickness L1≥1 mm.