Low-Temperature Dielectric Anisotropy Driven by an Antiferroelectric Mode in 
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Casals, Blai; Schiaffino, A.; Casiraghi, Arianna; Hämäläinen, Sampo J.; González, Diego López; Dijken, Sebastiaan van; Stengel, Massimiliano; Herranz, G.

doi:10.1103/physrevlett.120.217601

Cited by 24 publications

(22 citation statements)

References 45 publications

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“…1(b). It contains a a1/a2 twin configuration [41] When the initial kinetic energy of electrons is very low, e.g., 0.13 meV (Fig. 5), the interaction of electrons with the surface is similar to that in Fig.…”

Section: A Simulationsmentioning

confidence: 75%

Interaction of low-energy electrons with surface polarity near ferroelastic domain boundaries

Zhao

Barrett

et al. 2019

Phys. Rev. Materials

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We derive surface polarity at and near ferroelastic domain boundaries from molecular dynamics simulations based on an ionic spring model. Interatomic gradient forces lead to flexoelectricity which, in turn, generates polarity at the surface and in twin boundaries. We then derive generic properties of electron scattering spectra equivalent to those observed in low-energy electron microscopy (LEEM) and mirror electron microscopy (MEM) experiments. Negatively (positively) charged surfaces reflect (attract) incident electrons with low kinetic energy. The electron images reveal the valley and ridge surface structures near the intersection of the twin boundary and the surface. Polarity in surface layers is predicted to be visible in LEEM and MEM spectra at neutral surfaces, but much less when surfaces are charged. Inward polarity reflects electrons similar to negative surface charges, and outward polarity backscatters electrons like positive surface charges. Both the polarity in the twin boundary and the physical topography scatter electrons, consistent with experimental LEEM and MEM experiments on CaTiO 3 with (001) and (111) surface terminations.

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Section: A Simulationsmentioning

confidence: 75%

Interaction of low-energy electrons with surface polarity near ferroelastic domain boundaries

Zhao

Barrett

et al. 2019

Phys. Rev. Materials

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“…Indeed, field-induced changes of ferroelastic strains were reported for CaTiO 3 [4], a definitely nonpolar material where twin walls carry polarity [5]. SrTiO 3 is a particularly relevant case that comprises polar domain walls and a high dielectric anisotropy at low temperatures [6]. This material exhibits massive shifts of domain walls under applied electric fields, which go far beyond small bending effects as seen in friction experiments [7,8] and represent mesoscopic strain-driven domain movements [9][10][11][12].…”

mentioning

confidence: 97%

Electric-field-induced avalanches and glassiness of mobile ferroelastic twin domains in cryogenic SrTiO3

Casals

Dijken

Herranz

et al. 2019

Phys. Rev. Research

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Domain motion during ferroelectric switching has been recently suggested to follow scale-invariant avalanche dynamics. An interesting question concerns the dynamics of ferroelastic materials where the bulk material is nonpolar, while the polarity arises at domain walls only. We tackle this issue by investigating the dynamics of ferroelastic twins in SrTiO 3 where the movement of domains is driven mainly by the anisotropic dielectric response at low temperatures. We find that the dynamics of the twin reconfiguration under electric field proceeds by jerks, where the energy distribution is power-law distributed, indicating avalanche dynamics. Avalanche exponents are sensitive to the complexity of the twin pattern structure, reflecting glassiness when twins are interwoven and forming junctions at the intersections between domain walls. This "glassy" behavior is attributed to the pinning originated by these self-generated defects during jamming between twins.

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“…The retraction of needle domains over larger temperature intervals is commonly observed [16,31,62] and has been explained in terms of the elastic properties of the ferroelastic domain structures [11,12]. Moreover, the collective response of such ferroelastic domain patterns displays hallmarks for a glassy behavior as in case of low temperature relaxations during friction experiments [46] with similarities to patterns in magnetic spiral systems [63].…”

Section: Resultsmentioning

confidence: 89%

“…In a different scenario, the observed electric movement of needle domains in SrTiO 3 was shown to stem mainly from the dielectric anisotropy which expands or shrinks a domain [31] so that one might conclude that electric switching requires either dielectric anisotropy or the rapid formation of dislocations. To test this hypothesis we used a dielectrically isotopic, ferroelastic toy model to show that a needle domain can also be moved by an electric field even when the dielectric response is isotropic.…”

Section: Introductionmentioning

confidence: 97%

Electrically driven ferroelastic domain walls, domain wall interactions, and moving needle domains

Ding

et al. 2019

Phys. Rev. Materials

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Ferroelastic domains generate polarity near domain walls via the flexoelectric effect. Applied electric fields change the wall dipoles and generate additional dipoles in the bulk. Molecular dynamics simulations show that the thickness of domain walls changes when an electric field is applied to the sample. Fields parallel to the walls lead to expansion of the wall thickness while fields perpendicular to the wall lead to shrinking of the wall thickness. The interactions between polar domain walls expand over more than 45 unit cells, the resulting forces change the wall-wall distances if pinning effects are small. The interaction increases nonlinearly with decreasing wall-wall distances favoring equal wall distances as the consequence of energy minimization under the constraints of a constant number of domain walls. Even for small groups of three walls the sequence of walls is locally periodic: assemblies of three parallel domain walls arrange themselves so that the intermediate domain wall is located exactly in the middle between the two outer walls. The driving force is appreciable if the distance between the outer domain walls is below approximately 30 lattice units. Pairs of domain walls often form needle domains where the shaft of the needle is ca. 3 lattice units wide. The movement of needle domains under applied electric field was simulated. The advancement and retraction of needles is larger in finite samples with charge-free surfaces than under periodic boundary conditions in the bulk. The needle tip moves even more freely when the sample surface is charged.

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Low-Temperature Dielectric Anisotropy Driven by an Antiferroelectric Mode in SrTiO3

Cited by 24 publications

References 45 publications

Interaction of low-energy electrons with surface polarity near ferroelastic domain boundaries

Interaction of low-energy electrons with surface polarity near ferroelastic domain boundaries

Electric-field-induced avalanches and glassiness of mobile ferroelastic twin domains in cryogenic SrTiO3

Electrically driven ferroelastic domain walls, domain wall interactions, and moving needle domains

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