We investigate effects of doping on 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 fundamental condition on DFT ionization energies. The approach is further validated by CCSD(T) calculations for embedded clusters. We demonstrate that the concentration of oxygen vacancies at a doped oxide surface is largely determined by formation of a macroscopically extended space charge region.
@article{arxiv.1305.5157,
title = {Concentration of Vacancies at Metal Oxide Surfaces: Case Study of MgO (100)},
author = {Norina A. Richter and Sabrina Sicolo and Sergey V. Levchenko and Joachim Sauer and Matthias Scheffler},
journal= {arXiv preprint arXiv:1305.5157},
year = {2013}
}