Toroidal polar topology in strained ferroelectric polymer

Abstract

Polar topological texture has become an emerging research field for exotic phenomena and potential applications in reconfigurable electronic devices. We report toroidal topological texture self-organized in a ferroelectric polymer, poly(vinylidene fluoride-ran-trifluoroethylene) [P(VDF-TrFE)], that exhibits concentric topology with anticoupled chiral domains. The interplay among the elastic, electric, and gradient energies results in continuous rotation and toroidal assembly of the polarization perpendicular to polymer chains, whereas relaxor behavior is induced along polymer chains. Such toroidal polar topology gives rise to periodic absorption of polarized far-infrared (FIR) waves, enabling the manipulation of the terahertz wave on a mesoscopic scale. Our observations should inform design principles for flexible ferroic materials toward complex topologies and provide opportunities for multistimuli conversions in flexible electronics.

Engineering polar vortex from topologically trivial domain architecture

“…Unlike their ferromagnetic counterpart, ferroelectrics usually exhibit strong anisotropy that favors particular polar axes, and polarization rotation rarely occurs 5 . As a result, vast majority of polar structures naturally emerging in a ferroelectric are topologically trivial, and nontrivial polar topologies such as closure-domain 6 , 7 , vortex 8 , 9 , skyrmion 10 , meron 11 , and vortex-antivortex pair 12 have only recently been observed in reduced dimensions. It is now understood that in nanostructures such as nanodisks 13 , nanorods 14 , nanodots 15 , nanoislands 16 – 20 , and nanoplates 21 , electrostatic force dominates polar crystalline anisotropy, forcing polarization rotation and thus the formation of vortex.…”

Recent Advances in Multilayer‐Structure Dielectrics for Energy Storage Application

“…[ 49 , 62 , 63 , 64 , 65 , 66 , 67 ] In addition, the interaction of lattice, orbitals, charges, and spins at the heterogeneous interface produces peculiar physical properties, such as “improper ferroelectricity” in short‐period superlattices, ordered vortex arrays in mid‐period superlattices, and flux‐closed domain structures in large‐period superlattices. [ 68 , 69 , 70 , 71 , 72 , 73 ] These phenomena are important for researchers to understand the involved physical phenomena. The influence of this novel properties on the energy storage characteristics of multilayer dielectric needs to be explored.…”

Whirls and swirls of polarization

“…By Sarah E. Herrick and Judith E. Allen I t is estimated that ~66% of patients who have gastrointestinal surgery will develop adhesions (1). These bands of scar tissue arise in the abdominal cavity and can lead to small bowel obstruction and infertility in women as well as severe chronic abdominal pain.…”

“…In return, they have observed exotic phenomena and physics. On page 1050 of this issue, Guo et al (1) provide another example of how the exacting control of materials is producing effects one thought impossible to achieve. They created self-assembled topological and toroidal polarization textures-that is, a toroidal polarization arrangement in which the polar toroidal dipole configuration corresponds to the field of a solenoid bent into a torus (see the figure, bottom) in ferroelectric polymers.…”