On the origin of the reconstruction of LaAlO3 {100} surfaces

Based on previous studies of LaAlO3 {100} surfaces by molecular dynamics simulations the origin of AlO2 surface reconstruction is described in a detailed way. It is found that the driving mechanism fbr such reconstruction is a combined effect of all the unbalanced interatomic forces produced by the abundance of penta-coordinated aluminium ions at the surface, which appear upon cleavage of the original crystal, and in the process of reconstruction rearrange themselves in order to occupy lower energy positions, The 5 x 5 surface reconstruction experimentally observed is evidenced by a thorough analysis of the molecular dynamics results. (C) 1997 Elsevier Science B.V.