Point defects on MgO surface

Pd particle deposition on the MgO surface is one of the more thoroughly studied metal-oxide systems. It has been found that the point defects on the MgO surface, such as neutral oxygen vacancy, would greatly facilitate the binding properties between the metal cluster and MgO surface, dominate the cluster structures, and be responsible for the dispersion of metal islands in the metallic particle deposition. Some experimental efforts investigated the nucleation and growth modes of metal clusters on MgO surfaces. It was suggested, experimentally, that the nucleation may mostly occur at point defects and that the cluster growth corresponds to the nearly complete condensation regime, namely the cluster with island shapes. Moreover, the charging of Pd clusters upon adsorption is expected on an ultra thin MgO film but not on MgO single crystals.

Cluster Formation Model in Vapor Deposition of Pd Atoms on the Perfect MgO(100)
Surface and on Its Surface Oxygen Vacancy, Journal of physical chemistry, 2008
http://pubs.acs.org/cgi-bin/article.cgi/jpccck/2008/112/i35/pdf/jp804082d.pdf