12 research outputs found
Average Case Behavior of Distributed Extrema-Finding Algorithms
Coordinated Science Laboratory was formerly known as Control Systems LaboratoryNational Science Foundation / MCS-8217445Eastman Kodak Compan
Dynamic Tilting of Ferroelectric Domain Walls Caused by Optically Induced Electronic Screening
Optical excitation perturbs the balance of phenomena selecting the tilt
orientation of domain walls within ferroelectric thin films. The high carrier
density induced in a low-strain BaTiO3 thin film by an above-bandgap ultrafast
optical pulse changes the tilt angle that 90{\deg} a/c domain walls form with
respect to the substrate-film interface. The dynamics of the changes are
apparent in time-resolved synchrotron x-ray scattering studies of the domain
diffuse scattering. Tilting occurs at 298 K, a temperature at which the a/b and
a/c domain phases coexist but is absent at 343 K in the better ordered
single-phase a/c regime. Phase coexistence at 298 K leads to increased
domain-wall charge density, and thus a larger screening effect than in the
single-phase regime. The screening mechanism points to new directions for the
manipulation of nanoscale ferroelectricity
Dynamic Tilting of Ferroelectric Domain Walls via Optically Induced Electronic Screening
Optical excitation perturbs the balance of phenomena selecting the tilt
orientation of domain walls within ferroelectric thin films. The high carrier
density induced in a low-strain BaTiO3 thin film by an above-bandgap ultrafast
optical pulse changes the tilt angle that 90{\deg} a/c domain walls form with
respect to the substrate-film interface. The dynamics of the changes are
apparent in time-resolved synchrotron x-ray scattering studies of the domain
diffuse scattering. Tilting occurs at 298 K, a temperature at which the a/b and
a/c domain phases coexist but is absent at 343 K in the better ordered
single-phase a/c regime. Phase coexistence at 298 K leads to increased
domain-wall charge density, and thus a larger screening effect than in the
single-phase regime. The screening mechanism points to new directions for the
manipulation of nanoscale ferroelectricity