First-principles thermodynamics of coherent interfaces in samarium-doped ceria nanoscale superlattices.
Nanoscale superlattices of samarium-doped ceria layers with varying doping levels have been recently proposed as a novel fuel cell electrolyte. We calculate the equilibrium composition profile across the coherent {100} interfaces present in this system using lattice-gas Monte Carlo simulations with long-range interactions determined from electrostatics and short-range interactions obtained from ab initio calculations. These simulations reveal the formation of a diffuse, nonmonotonic, and surprisingly wide (11 nm at 400 K) interface composition profile, despite the absence of space charge regions.
Engineering and Applied Science Division, California Institute of Technology, Pasadena, California 91125, USA. avdw@alum.mit.edu
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van de Walle
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Ellis