相关论文: Vortex states in a PbTiO$_3$ ferroelectric cylinde…
The wealth of complex polar topologies recently found in nanoscale ferroelectrics result from a delicate balance between the materials intrinsic tendency to develop a homogeneous polarization and the electric and mechanic boundary…
Bounded charges induced by the polarization gradient in finite-size ferroelectrics are known to produce the unfavorable depolarization electric field that suppresses the uniform ferroelectric state. To reduce the depolarization energy the…
In the early 2000s, low dimensional systems were predicted to have topologically nontrivial polar structures, such as vortices or skyrmions, depending on mechanical or electrical boundary conditions. A few variants of these structures have…
We report from first-principles-based atomistic simulations that ferroelectricity can be sustained in PbTiO3 nanoparticles of only a few lattice constants in size as a result of a toroidal ordering. We found that size-induced topological…
A complete understanding of the mechanisms for dielectric relaxation in relaxor ferroelectrics remains elusive. We used a structural refinement framework that integrates several types of experimental data to identify the nanoscale…
Ferroelectric materials embedded with dielectric inclusions offer a unique platform for exploring novel topological polar textures. Using first-principles-based atomistic simulations, we investigate the polarization behavior of a BaTiO$_3$…
The piezoelectric response is a measure of the sensitivity of a material's polarization to stress or its strain to an applied field. Using in-operando x-ray Bragg coherent diffraction imaging, we observe that topological vortices are the…
Phase transformation in finite-size ferroelectrics is of fundamental relevance for understanding collective behaviors and balance of competing interactions in low-dimensional systems. We report a first-principles effective Hamiltonian study…
Ferroelectrics are characterized by domain structures as are other ferroics. At the nanoscale though, ferroelectrics may exhibit non-trivial or exotic polarization configurations under proper electrostatic and elastic conditions. These…
In the framework of the Landau-Ginzburg-Devonshire approach coupled with electrostatic equations, we performed finite element modeling of the polarization behavior in a ferroelectric barium titanate core covered with a tunable paraelectric…
Polar chiral structures have recently attracted much interest within the scientific community, as they pave the way towards innovative device concepts similar to the developments achieved in nanomagnetism. Despite the growing interest, many…
We report the emergence of a transverse dielectric response in PbTiO$_{3}$/SrTiO$_{3}$ superlattices hosting polar vortex structures. Using second-principles simulations, we find that an electric field applied along one direction induces…
Polar topologies, such as vortex and skyrmion, have attracted significant interest due to their unique physical properties and promising applications in high-density memory devices. Currently, most polar vortices are observed in…
Composite materials comprised of ferroelectric nanoparticles in a dielectric matrix are being actively investigated for a variety of functional properties attractive for a wide range of novel electronic and energy harvesting devices.…
Ferroelectric thin films under epitaxial strain exhibit a variety of vortex-like topological polarization textures. To analyze them, we build on the Ginzburg-Landau-Devonshire framework and extend the previously introduced soft-domain…
There are increasing evidences that ferroelectric states at the nanoscale can exhibit fascinating topological structures including polar vortices and skyrmions,akin to those observed in the ferromagnetic systems. Here we report the…
The behaviour of the cross-sectional polarization field is explored for thin nanowires of barium titanate from first-principles calculations. Topological defects of different winding numbers have been obtained, beyond the known textures in…
Ferroelectric materials display exotic polarization textures at the nanoscale that could be used to improve the energetic efficiency of electronic components. The vast majority of studies were conducted in two dimensions on thin films, that…
Although ferroelectric materials are characterised by their parallel arrangement of electric dipoles, in the right boundary conditions these dipoles can reorganize themselves into vortices, antivortices and other non-trivial topological…
In this paper we study the size effects of the ferroelectric nanotube and nanowire phase diagrams and polar properties allowing for radial stress and depolarization field influence. The approximate analytical expression for the…