MATERIALS SCIENCE COLLOQUIUM

SPEAKER: Dr. Dillon Fong
Materials Science Division
Argonne National Laboratory
TITLE: "In Situ Studies on the Effect of Oxygen Partial Pressure on Ferroelectric Thin Films"
DATE: Thursday, September 8, 2011
TIME: 11:00 a.m.
PLACE: Building 212 / A-157
HOST: Paul Fuoss

Refreshments will be served at 10:45 a.m.

ABSTRACT: From our previous studies [1], it is known that the behavior of ferroelectric thin films can depend strongly on oxygen partial pressure (pO2) as well as temperature. This can have significant implications in understanding both ferroelectricity and the reactivity of oxide surfaces. Others have recently shown that polarization at BaTiO3 and LiNbO3 surfaces can affect adsorption behavior [2,3], suggesting that ferroelectricity may be a potential route for modulating surface catalytic properties. We use in situ synchrotron x-ray scattering to study the pO2 dependent properties of PbTiO3 and BaTiO3 films grown on SrRuO3 or Nb-doped SrTiO3 substrates. We describe the effect of pO2 on polarization and examine the differences between the PbTiO3 and BaTiO3 in terms of oxygen reactivity and surface structure.

[1] R.-V. Wang, D. D. Fong, F. Jiang, M. J. Highland, P. H. Fuoss, et al., Phys. Rev. Lett. 102, 047601 (2009).
[2] D. Li, M. H. Zhao, J. Garra, A. M. Kolpak, A. M. Rappe et al., Nature Mater. 7, 473 (2008).
[3] J. Garra, J. M. Vohs, and D. A. Bonnell, Surf. Sci. 603, 1106 (2009).