The transport of O in (La1-xSrx)0.95FeyMn1-yOz, where x was between 0 and 0.30 and y was between 0 and 0.7, was investigated by means of thermogravimetry at 800 to 1000C; during repeated changes between N2 and N2/O2 atmospheres. At low substitution levels, the materials were found to be hyperstoichiometric, with respect to O, in air at 1000C. At the highest substitution levels, they changed to being hypostoichiometric. The O transport kinetics and diffusion coefficients were deduced from weight changes as a function of time, and from scanning electron microscopic and X-ray data on crystallite dimensions., Diffusion coefficients which ranged from 10-15 to 10-11cm2/s were reported for powdered samples.

Thermogravimetric Studies of Oxygen Stoichiometry and Oxygen Transport Kinetics in Lanthanum Strontium Ferrite Manganites. J.Kjr, I.G.K.Andersen, E.Skou: Solid State Ionics, 1998, 113-115, 387-92