A COMPUTATIONAL MODEL FOR GROWTH OF (100) SRTIO3 AND (001) YBA2CU3O7 OXIDE-FILMS

A computational model has been developed to describe the growth of oxide films of (100) SrTiO3 and (001) YBa2Cu3O7. The ionic model treats two-dimensional periodic films within the scope of the shell model. The non-polar SrO and TiO2 layers of (100) SrTiO3 are stable, as well as the CuO basal plane of (001) YBa2Cu3O7. Growth on these surfaces proceeds energetically most favorably by the bulk sequence, but in which the layers added have zero or near zero charge per unit surface mesh. The oxygen content of the layers is varied to achieve this condition. Surface diffusion barriers on the (001) YBa2Cu3O7 surfaces are estimated from the adsorption energies of ions at various sites on the surface. The barriers are found to be much less than the corresponding barriers calculated in the bulk.