Screening of ferroelectric domains on BaTiO 3(001) surface by ultraviolet photo-induced charge and dissociative water adsorption

Abstract

The surface potential contrast between oppositely polarized ferroelectric domains of a BaTiO 3 (001) single crystal under ultraviolet (UV) illumination before and after the dissociative adsorption of water is measured using the transition from mirror electron microscopy to low-energy electron microscopy. Both photo-generated free charge carriers and dissociative adsorption of water are effective screening mechanisms of the surface polarization charge. The screening rate is dominated by drift, whereas the relaxation in the absence of UV light is driven by thermal diffusion. Surface chemistry plays an important role in the surface charge dynamics. © 2012 American Institute of Physics.