The Effect of Polarization on Local Electronic Structure in Ferroelectric Nano-Domains in BaTiO$_{3}$

Novel ferroelectric BaTiO$_{3}$ applications ranging from sensors to nanogenerators require a detailed understanding of atomic interactions at surfaces. Single crystals provide a platform that allows the exploitation of surface physical and chemical properties that can be readily transferred to other ABO$_{3}$ perovskites. The processes that result in the atomic and electronic structures of surfaces in tandem with polarization of domains are necessary steps towards understanding BaTiO$_{3}$. Here we treat BaTiO$_{3}$ surface using sputtering-annealing cycles that yield the (6x1) reconstruction. We demonstrate that it is possible to pole a thin BaTiO$_{3}$ single crystal in ultra high vacuum using scanning tunneling microscopy (STM). We determine that we can prepare BaTiO$_{3}$ using \textit{in-situ} annealing that allows us to control the size of poled region to 40nm. We pole in constant-current mode in STM by applying a bias of less than 10 V between tip and sample for 100ms. STM and scanning tunneling spectroscopy characterization allow us to map topography and local density of states, respectively. For a given unique pulse, the poled domains show a fluctuating electronic occupation of conduction bands and shifting of valence band. We will also discuss the effect of polarization on molecular adsorption.