Defect chemistry and electrical conductivity of Sm-doped La1−xSrxCoO3−δ for solid oxide fuel cells
Mårten E. Björketun, Ivano E. Castelli, Jan Rossmeisl, Thomas Olsen, Kenji Ukai, Michiaki Kato, Gilles Dennler, and Karsten W. Jacobsen
We have calculated the electrical conductivity of the SOFC cathode contact material La1−xSrxCoO3−δ at 900 K. Experimental trends in conductivity against x, and against δ for fixed x, are correctly reproduced. Furthermore, we have studied the chemistry of neutral and charged intrinsic and extrinsic defects (dopants) in La0.5Sr0.5CoO3 and calculated the conductivity of the doped systems. In particular, we find that doping with Sm on the La site should enhance the conductivity, a prediction that is subsequently confirmed by electrical conductivity measurements.
The database contains all the investigated perovskite structures and the reference energies used to calculate the stability of the candidate materials.
nSr: Number of Sr atomsnCo: Number of Co atomsnO: Number of O atoms
nDOP: Number of dopant atoms
dopant: chemical element of the dopant atom(s)nvo: Number of O vacanciesconf: Configuration for the LSCO perovskites or "refs" for the reference systems used to calculate the stabilitysigma: Value of sigma
Conductivity of LSCO
The script available here plots the conductivity as a function of the Sr content for the La1−xSrxCoO3−δ perovskites.
We add here some information regarding the manuscript. In particular, we show here the calculated formation free energies of vacancies (interstitials/anti-sites) in different charge states as a function of Fermi-level position within the theoretical band gap of La0.5Sr0.5CoO3: