Synthesis and Oxygen Permeation Properties of Sr2.7La0.3Fe2-yMyO7-d (M = Mn, Co and Ni)

F. PRADO; A. MANTHIRAM

Indianapolis

Encuentro; The American Ceramic Society’s 103nd Annual Meeting and Exposition; 2001

The American Ceramic Society

Perovskite-related intergrowth oxides Sr2.7Lao.3Fe2-yMy07-d (M = Mn, Co and Ni) have been synthesized by a sol-gel method for 0 < y < 1.0. The samples have been characterized by X-ray powder diffraction, thermogravimetric analysis, and transport measurements. The substitution of Mn, Co or Ni for Fe does not change the tetragonal symmetry of the crystal structure at room temperature. Both the electrical conductivity and oxygen nonstoichiometry at high temperature decrease in the order Ni > Co > Fe > Mn. However, the Co doped ceramic membranes exhibit higher oxygen permeation flux values than Ni-doped samples. For Ni- and Co-doped samples, bulk ionic transport controls the oxygen permeation rate.