Local potential and polarization screening on ferroelectric surfaces - art. no. 125411

Electrostatic force microscopy and scanning surface potential microscopy ar e applied to study force gradient and surface potential on BaTiO3(100) surf ace. Surface potential evolution during a ferroelectric/paraelectric phase transition and the potential distribution near moving domain walls allow th e relationship between potential polarity and polarization orientation. Res ults indicate that polarization bound charge is completely screened on this surface and domain potential is reverse to that expected from domain polar ity. Surface potential is attributed to the formation of double layer due t o the complete screening of polarization charge. The absolute value of the measured potential difference between domains of opposite polarity suggests that surface adsorbates play a governing role in potential formation mecha nism, though intrinsic screening by free carriers is not completely exclude d.