Static and transient model analysis on expansion behavior of LaCrO3 under an oxygen potential gradient

Doped lanthanum chromites show lattice expansion under high temperature red ucing atmospheres. We have proposed a numerical simulation model for analyz ing the static and the transient expansion behavior of the doped lanthanum chromites under a stationary oxygen potential gradient or a stepwise change of oxygen potential in the atmosphere. A lanthanum chromite interconnector plate, 100 X 100 X 3 mm, was found to warp under a stable solid oxide fuel cell operating condition. The maximum displacement of the center part norm al to the originally flat surface was calculated to be about 0.77 mm. A ste pwise change of the atmospheric condition caused a transient oxygen potenti al gradient in a lanthanum chromite rod, 3 x 3 x 20 mm, resulting in a defo rmation of the sample. The calculated tensile stress coming from the transi ent deformation was as high as 50 MPa or more. (C) 2000 The Electrochemical Society. S0013-4651(00)04-034-9. All rights reserved.