The internal stress in an anode-supported type solid oxide fuel cell (SOFC) was evaluated by in-situ measurement using micro Raman scattering spectroscopy. The new method evaluating stress focused on Raman spectra of samarium-doped ceria (SDC) which was used as an interlayer in SOFC. Because the shift of F_<2g> Raman peak position and peak width in SDC was dependent on the change of stress, temperature and Sm concentration, by measuring the dependencies respectively, the stress could be calculated. We performed this method in the purchased cells of conventional anode-supported type SOFC under thermal cycles, which simulate start-and-stop of SOFC. In this study, three thermal cycles were applied. Observed results suggested that not only thermal stress relaxation but also diffusion of samarium from an interlayer to an electrolyte, and stress relaxation by plastically deformation were occurred.
