Ab initiomolecular dynamics study of hydrogen removal by ion–surface interactions

The energy dependence of surface reactions has been investigated through ab initio MD simulations for collisions between Al1+ and a gibbsite surface. No change in surface composition was observed for 0 eV initial kinetic energy of Al1+. An increase in energy to 3.5 eV resulted in extended surface migration of hydrogen, subsequent H2 formation and desorption from the surface. These results may be understood based on thermodynamics and an increase in entropy upon H2 formation. They are of fundamental importance for an increased understanding of thin film growth through the correlation between ion energy and film composition. They may also indicate a pathway to affect impurity incorporation during film growth.