Lattice expansion of acceptor-doped lanthanum chromites under high-temperature reducing atmospheres

The dimensional changes of doped lanthanum chromites (LaCrO3) upon reductio n were investigated by thermal expansion measurements in oxidizing and redu cing atmospheres; Judging from the crack formation in these experiments, an empirical guideline for materials selection of LaCrO3-based interconnector s in solid oxide fuel cells has been identified that materials showing rela tive linear expansions of less than 0.1% are to be used. It was also found that the lattice expansion increased with decrease of oxygen partial pressu re (P (O-2)) and showed a trend to saturate at very low P (O-2). This trend has successfully been elucidated by a simple model derived by using Vegard 's law.