Thermodynamics and kinetics of the Schottky defect at terraces and steps on the MgO(001) surface.
The Schottky defects at both the flat MgO(001) surface and the monatomic-step edge have been investigated by equilibrium molecular dynamics simulations. The formation enthalpy as a function of the distance between the Mg and O vacancies that form a Schottky defect have been calculated and discussed. We conclude that a step edge is a stable location for a vacancy. The migration mechanism has been elucidated and an intermediate state has been identified. The associated activation enthalpies have been determined in the 700-1100 K temperature range. Both magnesium and oxygen vacancies at the surface are very mobile and can play a role during the crystal growth.
Antoshchenkova
Ekaterina
E
Laboratoire des Solides Irradiés, Ecole Polytechnique, CEA-DSM, CNRS, 91128 Palaiseau, France. ekaterina.antoshchenkova@polytechnique.edu
Hayoun
Marc
M
Geneste
Grégory
G
Finocchi
Fabio
F