The effects of Fe-substitution on the crystal structure and oxygen permeability of PrBaCo2O5+δ

A series of double layered perovskites, PrBaCo2-xFexO5+delta (x=0, 0.2, 0.5, 1, 1.5, and 2), are successfully prepared employing a solid state reaction. The effects of Fe substitution on the crystal structure and oxygen transport properties of PrBaCo2O5+delta were investigated by X-ray diffraction and oxygen permeation experiments. X-ray diffraction patterns confirm that PrBaCo2O5+delta, PrBaCo1.8Fe0.2O5+delta, PrBaCo1.5-Fe0.5O5+delta, and PrBaFe2O5+delta exhibit an orthorhombic perovskite structure, while PrBaCoFeO5+delta, and PrBaCo0.5Fe1.5O5+delta crystallize in a cubic perovskite. The oxygen permeation flux of PrBaCo2-xFexO5+delta is found to decrease with increasing Fe content. Among the compositions, PrBaCo2O5+delta shows the highest oxygen permeation flux of 1.89 x 10(-7) mol cm(-2) s(-1) at 900 degrees C under an air/helium atmosphere. (C) 2013 Elsevier B.V. All rights reserved.