Thomas Tybell

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Ferroelectric switching and nanoscale domain dynamics were investigated using atomic force microscopy on monocrystalline Pb(Zr(0.2)Ti(0.8))O(3) thin films. Measurements of domain size versus writing time reveal a two-step domain growth mechanism, in which initial nucleation is followed by radial domain wall motion perpendicular to the polarization(More)
Scanning transmission electron microscopy (STEM) data with atomic resolution can contain a large amount of information about the structure of a crystalline material. Often, this information is hard to extract, due to the large number of atomic columns and large differences in intensity from sublattices consisting of different elements. In this work, we(More)
IO N As a room-temperature multiferroic, BiFeO 3 has been intensively investigated for both magnetoelectric devices and non-volatile ferroelectric memory applications. [ 1–3 ] BiFeO 3 , having a rhombohedral unit cell, has antiferromagnetic, ferroelectric and ferroelastic order parameters. Since BiFeO 3 exhibits coupling between spontaneous electric(More)
In this article, the effects of the transmission electron microscopy (TEM) specimen preparation techniques, such as ion milling and tripod polishing on perovskite oxides for high-resolution TEM investigation, are compared. Conventional and liquid nitrogen cooled ion milling induce a new domain orientation in thin films of SrRuO(3) and LaFeO(3) grown on(More)
Arrays of ferroelectric lead titanate (PbTiO(3)) nanorods have been grown on a substrate by a novel template-free method. Hydrothermal treatment of an amorphous PbTiO(3) precursor in the presence of a surfactant and PbTiO(3) or SrTiO(3) substrates resulted in the growth of PbTiO(3) nanorod arrays aligned perpendicular to the substrate surface. Two steps in(More)
Using photoemission electron microscopy in combination with X-ray magnetic linear dichroism, we report reconfiguration upon nanostructuring of the antiferromagnetic domain structure in epitaxial LaFeO3 thin films. Antiferromagnetic (AFM) nanoislands were synthesized using a dedicated process, devised to define nanostructures with magnetic order embedded in(More)
We report the fabrication of PbTiO(3) nanomesas down to 30 nm lateral size and 4 nm high on nanostructured SrRuO(3)/SrTiO(3) templates by off-axis radio frequency magnetron sputtering. The templates were prepared using a top-down lithography approach based on scanning tunneling microscopy. The growth rate of the PbTiO(3) nanomesas was found to decrease with(More)
Hexagonal manganites, h-RMnO3 (R=Sc, Y, Ho-Lu), have been intensively studied for their multiferroic properties, magnetoelectric coupling, topological defects and electrically conducting domain walls. Although point defects strongly affect the conductivity of transition metal oxides, the defect chemistry of h-RMnO3 has received little attention. We use a(More)
The technologically important exchange coupling in antiferromagnetic/ferromagnetic bilayers is investigated for embedded nanostructures defined in a LaFeO(3)/La(0.7)Sr(0.3)MnO(3) bilayer. Exploiting the element specificity of soft X-ray spectromicroscopy, we selectively probe the magnetic order in the two layers. A transition from perpendicular to parallel(More)
Thresholds for beam damage have been assessed for La0.7Sr0.3MnO3 and SrTiO3 as a function of electron probe current and exposure time at 80 and 200kV acceleration voltage. The materials were exposed to an intense electron probe by aberration corrected scanning transmission electron microscopy (STEM) with simultaneous acquisition of electron energy loss(More)