Paper SS-ThA3
Surface Reconstructions of BaTiO₃(001): STM Study

Thursday, November 3, 2011, 2:40 pm, Room 107

BaTiO₃ is currently used in Random Access Memories and is a versatile material with many potential applications. Ferroelectricity at a surface provides unique possibilities to examine mechanisms of molecular adsorption. Experimentally, the polarization can be manipulated in situ by negatively and positively poling the surface. In this manner, the interaction with foreign gaseous species can be controlled. It is necessary to develop fundamental understanding of BaTiO₃ surfaces in order to control the ferroelectric polarization and consequent interactions with adsorbates and in devices. Recent advances have indeed shown that polarization affects molecular adsorption of a variety of molecules; however, the mechanistic processes are not yet understood. Here we present STM of atomically resolved reconstructions, (√5x√5) R26.6°and (3×1) and relate water assoprtion to local polarization. Structural variations and adsorption sites will be discussed in terms of Density Functional Theory predictions. Preliminary results of the interaction of BaTiO₃ (001)’s surface and CO₂ will be presented as well.