ON THE ORIGIN OF THE RECONSTRUCTION OF LAALO3 (100)SURFACES

Based on previous studies of LaAlO3 {100} surfaces by molecular dynami cs simulations the origin of AlO2 surface reconstruction is described in a detailed way. It is found that the driving mechanism fbr such rec onstruction is a combined effect of all the unbalanced interatomic for ces produced by the abundance of penta-coordinated aluminium ions at t he 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 experimental ly observed is evidenced by a thorough analysis of the molecular dynam ics results. (C) 1997 Elsevier Science B.V.