SIMS ANALYSIS OF MATERIALS TRANSPORT IN LANTHANUM CHROMITE INTERCONNECTS

摘要

The cation interdiffusion coefficient in alkaline-earth substituted lanthanum chromite is determined for the Sr~(2+)-La_(0.75)Ca_(0.25)CrO_3 case by using SIMS (secondary ion mass spectrometry). The bulk diffusion coefficient for interdiffusion between Sr~(2+) and Ca~(2+) is 1.2 × 10~(-19) m~2s~(-1)at 1273 K in p(O_2) = 10~5 Pa, 3.3 × 10~(-19) mV at p(O_2) = 10~3 Pa, and 7.0 × 10~(-21) m~2s~(-1) at p[O_2) = 10 Pa. The activation energy is 258 kJ mol~(-1) in the temperature range of 1173 ～ 1373 K at p(O_2) = 10~3 Pa. The grain boundary diffusion coefficients were found to be linear to p(O_2)~(1/2).