Nanometer control of the ferroelectric polarization in Pb(Zr0.2Ti0.8)O3 thin films

Using scanning probe microscopy and atomically smooth epitaxial Pb(Zr_0.2Ti_0.8)O₃ (PZT) thin films, we have investigated the possibility of controlling and modifying the ferroelectric polarization over large areas with submicron resolution. The films, which show a root-mean-square roughness of typically 2 A, could be uniformly polarized over areas as large as 2500 μm² , and regular arrays of circular domains with a diameter of less than 100 nm, as well as lines with a width of 100 nm, could be written at arbitrary positions within the uniformly polarized areas. This local control of the polarization spans ten orders of magnitude in area and is ultimately limited by the sample size. We also report on studies of the intrinsic domain structure in films showing both c- and a-axis orientations. These films were characterized by transmission electron microscopy and X-ray diffraction. Local investigations of the ferroelectric properties were performed, and correlations between the microstructure and the ferroelectric properties are discussed