Concentration of vacancies at metal-oxide surfaces: case study of MgO(100).
We investigate the effects of doping on the formation energy and concentration of oxygen vacancies at a metal-oxide surface, using MgO(100) as an example. Our approach employs density-functional theory, where the performance of the exchange-correlation functional is carefully analyzed, and the functional is chosen according to a condition on density-functional theory ionization energies. The approach is further validated by coupled-cluster calculations, including single, double, and perturbative triple substitutions, for embedded clusters. We demonstrate that the concentration of oxygen vacancies at a doped oxide surface is largely determined by the formation of a macroscopically extended space-charge region.
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
Norina A
NA
Richter
Sabrina
S
Sicolo
Sergey V
SV
Levchenko
Joachim
J
Sauer
Matthias
M
Scheffler