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

A thermogravimetric method has been used for the determination of the oxyge n chemical diffusion coefficients in La1-xSrxMnO3+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(-1 0) cm(2) s(-1) for the samples in the temperature range studied. The activa tion energy for oxygen chemical diffusion was determined to be 190-280 kJ m ol(-1) for the LSM samples. The magnitude of the chemical diffusion coeffic ients of the LSM samples does not depend on the strontium site occupation f actor.