Determination of the oxygen chemical diffusion coefficient in perovskites by a thermogravimetric method

A thermogravimetric method has been used for the determination of the oxygen chemical diffusion coefficients in La(1-x)Sr(x)MnO(3+delta); x=0; 0.05; 0.10; 0.15 (LSM). A temperature range of 700-1000 degreesC was studied. The chemical diffusion coefficient varies between 1.6.10(-13) and 1.8.10(-10) cm(2) s(-1) for the samples in the temperature range studied. The activation energy for oxygen chemical diffusion was determined to be 190-280 kJ mol(-1) for the LSM samples. The magnitude of the chemical diffusion coefficients of the LSM samples does not depend on the strontium site occupation factor.