Iron Exsolution Phenomena in Lanthanum Strontium Ferrite SOFC Anodes. (30th May 2017) - Götsch, Thomas
Abstract : The iron exsolution behavior of lanthanum strontium ferrite under reducing conditions is investigated using multiple ex situ and in situ methods. During heating experiments, an irreversible phase transition in oxygen-deficient environments from the rhombohedral to the cubic polymorph is witnessed in the form of a non-linear shift of the reflexes prior to the exsolution of metallic iron. Since this is not the case in oxidative environments, it leads to the conclusion that oxygen vacancies in the lattice stabilize the cubic phase. Also, the exsolution is shown to exhibit an Avrami-like behavior, suggesting a diffusion-limited process, where the transport of iron to the Fe-depleted surface-near region is the slowest step.