Chromium diffusion in lanthanum chromites

Tracer diffusion coefficients of chromium (50Cr) in alkaline-earth-doped lanthanum chromites were determined by secondary ion mass spectrometry (SIMS). The chromium diffusion coefficient in the bulk was about 1/100 of that of calcium in (La, Ca)CrO3 at T=1273 K. The chromium diffusion coefficient in (La, Sr)CrO3 (bulk) was smaller than that in (La, Ca)CrO3 (bulk). Grain boundary diffusion coefficients were 105 times larger than bulk diffusion coefficients. Material transport under the operating conditions of the solid oxide fuel cell (SOFC) is discussed.