Water adsorption induced in-plane domain switching on BaTiO_3 surface

摘要

In this study, the influences of the adsorption of water molecules on the changes in the atomic and electric structures of BaTiO_3 surface were investigated using ab initio calculation. Water molecules are molecularly and dissociatively adsorbed on the BaTiO_3 surface, which makes electrons transfer from water molecules to the BaTiO_3 surface. The redistribution of electrons in the BaTiO_3 surface layers weakens the Ba-O interactions and strengthens the Ti-O interactions, so that the Ti atom shifts in TiO_2 plane, i.e., an in-plane domain switching. The adsorption of water molecules on BaTiO_3 surfaces also results in a reduction in the surface rumpling.