Manifestation of dipole-induced disorder in self-assembly of ferroelectric and ferromagnetic nanocubes

Zablotsky, Dmitry; Rusevich, Leonid L.; Zvejnieks, G.; Kuzovkov, V. N.; Kotomin, E. A.

doi:10.1039/c9nr00708c

Cited by 10 publications

(16 citation statements)

References 118 publications

(189 reference statements)

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“…In nanoscale perovskites, the near-surface oxygen O 2À ions can be slightly displaced with respect to the metal ion of the same plane. Semi-empirical and quantum-chemical calculations of the dipole moments in BaTiO 3 perovskite structures [14,16] indicate that the surface rumpling of "naked" BaTiO 3 could result in an overall 〈001〉 dipole of %2000-5000 D in 20 nm nanocubes and λ ¼ 10 ÷ 50, which agrees with the experimental value.…”

Section: Magnitude Of Dipole Momentsupporting

confidence: 81%

“…The cooperative ordering of the individual displacements produces an overall ⟨001⟩ electric dipole moment μ in single‐domain BaTiO 3 nanocube pointing toward the cube's face . The relative strength of the dipolar interaction between colloidal particles and its role in the self‐assembly are determined by the ratio of the characteristic energy of interaction

\propto λ k_{B} T

to the average energy of the thermal fluctuations

β^{- 1} = k_{B} T

λ = \frac{1}{4 π ε_{r} ε_{0}} \frac{β μ^{2}}{σ^{3}}

where σ is the edge length of the nanocube. For

λ < 1

, the dispersive influence of the thermal motion suppresses particle association, whereas for

λ ≫ 1

, the interaction dominates and dipolar mesostructure rapidly forms even in dilute solutions …”

Section: Magnitude Of Dipole Momentmentioning

confidence: 99%

“…This interaction is modeled by the repulsive WCA 12‐6 potential

β U_{WCA} false(r_{i j} false) = 4 [{(δ r_{i j}^{- 1})}^{12} - {(δ r_{i j}^{- 1})}^{6} + \frac{1}{4}], r_{i j} \leq δ \sqrt[6]{2}

and projects a uniform elastic shell

\frac{1}{2} δ

around the cubic shapes reflecting the soft structure of the colloids ligated by an organic coat. The dipole–dipole interaction between two ⟨001⟩ (pointing toward cube faces) point dipoles

μ_{i}

and

μ_{j}

assigned to two nanocubes

β U_{dd} false(μ_{i}, μ_{j}, r_{bold-italici bold-italicj} false) = - \frac{λ}{r_{i j}^{3}} false[3 false({\overset{false^}{bold-italicμ}}_{i} \cdot {\overset{false^}{bold-italicr}}_{bold-italici bold-italicj} false) false({\overset{false^}{bold-italicμ}}_{j} \cdot {\overset{false^}{bold-italicr}}_{bold-italici bold-italicj} false) - {\overset{false^}{bold-italicμ}}_{i} \cdot {\overset{false^}{bold-italicμ}}_{j} false]

and the resulting forces, torques, and virial stress contributions are calculated using dipolar P 3 M as described previously . The interaction is calculated directly for nanocubes within a spherical cutoff, whereas for the long‐range part, the Fourier‐based Ewald summation on a mesh is used.…”

Section: Simulation Modelmentioning

confidence: 99%

“…The interaction is calculated directly for nanocubes within a spherical cutoff, whereas for the long‐range part, the Fourier‐based Ewald summation on a mesh is used. The Ewald splitting parameter is adjusted within an iterative procedure for the maximum accuracy of the scheme . The simulations are performed with HOOMD‐blue, which is a general‐purpose particle simulation toolkit, within the isothermal–isobaric (NPT) ensemble using Martyna–Tobias–Klein hybrid scheme (barostat‐thermostat) with periodic boundary conditions.…”

Section: Simulation Modelmentioning

confidence: 99%

“…The cooperative ordering of the individual displacements produces an overall 〈001〉 electric dipole moment μ in single-domain BaTiO 3 nanocube pointing toward the cube's face. [12] The relative strength of the dipolar interaction between colloidal particles and its role in the self-assembly are determined by the ratio of the characteristic energy of interaction ∝ λk B T to the average energy of the thermal fluctuations β À1 ¼ k B T [13,14] λ…”

Section: Magnitude Of Dipole Momentmentioning

confidence: 99%

See 4 more Smart Citations

Role of Intrinsic Dipoles in the Evaporation‐Driven Assembly of Perovskite Nanocubes into Energy‐Harvesting Composites

Zablotsky

Kuzovkov

Kotomin

2019

Physica Status Solidi (a)

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Efficient ambient energy scavenging exploiting piezoelectric properties of ferroelectric perovskites is an attractive green strategy to power low‐energy devices. In turn, the colloidal processing of the nearly monodisperse and highly crystalline single‐domain nanocubes of BaTiO3 is a promising route to produce oriented, high‐performance thin films for integration into nanostructured‐ferroelectric devices. Controlling the local behavior of nanocrystals is imperative for fabricating highly ordered assemblies, whereas the current picture of nanoscale polarization suggests a potential presence of significant electrodipolar interaction in ferroelectric nanoparticles. However, its role in the condensation of perovskite nanocubes remains unknown. The results of simulated self‐assembly and characterization of osmotically densified ensembles of dipolar nanocubes are reported. It is shown that in fact for solubilized BaTiO3 nanocubes, the polarization screening must be complete without appreciable dipole moment (below a few kBT), whereas stray interactions from incompletely screened surface charges are likely the major sources of disorder in self‐assembled architectures of SrTiO3.

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Section: Magnitude Of Dipole Momentsupporting

confidence: 81%

\propto λ k_{B} T

to the average energy of the thermal fluctuations

β^{- 1} = k_{B} T

λ = \frac{1}{4 π ε_{r} ε_{0}} \frac{β μ^{2}}{σ^{3}}

where σ is the edge length of the nanocube. For

λ < 1

, the dispersive influence of the thermal motion suppresses particle association, whereas for

λ ≫ 1

, the interaction dominates and dipolar mesostructure rapidly forms even in dilute solutions …”

Section: Magnitude Of Dipole Momentmentioning

confidence: 99%

“…This interaction is modeled by the repulsive WCA 12‐6 potential

β U_{WCA} false(r_{i j} false) = 4 [{(δ r_{i j}^{- 1})}^{12} - {(δ r_{i j}^{- 1})}^{6} + \frac{1}{4}], r_{i j} \leq δ \sqrt[6]{2}

and projects a uniform elastic shell

\frac{1}{2} δ

around the cubic shapes reflecting the soft structure of the colloids ligated by an organic coat. The dipole–dipole interaction between two ⟨001⟩ (pointing toward cube faces) point dipoles