Surface potential at a ferroelectric grain due to asymmetric screening of depolarization fields

Smearing of phase transition due to a surface effect or a bulk inhomogeneity in ferroelectric nanostructures.

The boundary conditions, customarily used in the Landau-type approach to ferroelectric thin films and nanostructures, have to be modified to take into account that a surface of a ferroelectric is a defect of a field type. The surface (interface) field is coupled to a normal component of polarization and, as a result, the second order phase transitions are generally suppressed and anomalies in r...

Surface screening of written ferroelectric domains in ambient conditions

We have combined Piezoresponse Force Microscopy and Kelvin Probe Force Microscopy (KPFM) to study screening charge dynamics in written domains on PbZr0.2Ti0.8O3 (PZT) thin film surfaces under a controlled environment and at variable temperature. The screening dynamics decayed exponentially on a timescale of tens of minutes, consistently with what we expected for water-mediated surface diffusion...

Enhanced diffusion due to active swimmers at a solid surface.

We consider two systems of active swimmers moving close to a solid surface, one being a living population of wild-type E. coli and the other being an assembly of self-propelled Au-Pt rods. In both situations, we have identified two different types of motion at the surface and evaluated the fraction of the population that displayed ballistic trajectories (active swimmers) with respect to those s...

Fast reduction of potential fields measured over an uneven surface to a plane surface

Nanodomains due to phason defects at a quasicrystal surface.

Among the three coexisting types of terraces found on the twofold surface of the d-Al-Cu-Co quasicrystal, nanodomains are essentially observed on the transition-metal rich ones, with a coherent interface boundary. Both clean surface and Ag growth analyses, demonstrate that nanodomain surfaces are structurally identical to one of the two other terraces, which contains 85 at. % Al. We provide evi...