Oxygen vacancies on MgO(100)

摘要: Abstract The electronic and atomic structures of nondashstoichiometric MgO {100} surfaces, with several densities neutral oxygen vacancies, have been studied using a semi-empirical Hartree-Fock method associated geometry optimization code. vacancies are periodically repeated in the surface top layer equal spacings. Strong electron redistributions take place on magnesiums which surround localized states appear gap below conduction band minimum. Their positions shift towards lower energies as vacancy density increases. energy formation is found to be close 10 eV at low densities. It strongly decreases deficiency grows, due electrostatic interactions. mechanisms responsible for displacements analysed.