Microscopic origins of the crystallographically preferred growth in evaporation-induced colloidal crystals

Unlike crystalline atomic and ionic solids, texture development due to crystallographically preferred growth in colloidal crystals is less studied. Here we investigate the underlying mechanisms of the texture evolution in an evaporation-induced colloidal assembly process through experiments, modeling, and theoretical analysis. In this widely used approach to obtain large-area colloidal crystals, the colloidal particles are driven to the meniscus via the evaporation of a solvent or matrix precursor solution where they close-pack to form a face-centered cubic colloidal assembly. Via two-dimensional large-area crystallographic mapping, we show that the initial crystal orientation is dominated by the interaction of particles with the meniscus, resulting in the expected coalignment of the close-packed direction with the local meniscus geometry. By combining with crystal structure analysis at a single-particle level, we further reveal that, at the later stage of self-assembly, however, the colloidal crystal undergoes a gradual rotation facilitated by geometrically necessary dislocations (GNDs) and achieves a large-area uniform crystallographic orientation with the close-packed direction perpendicular to the meniscus and parallel to the growth direction. Classical slip analysis, finite element-based mechanical simulation, computational colloidal assembly modeling, and continuum theory unequivocally show that these GNDs result from the tensile stress field along the meniscus direction due to the constrained shrinkage of the colloidal crystal during drying. The generation of GNDs with specific slip systems within individual grains leads to crystallographic rotation to accommodate the mechanical stress. The mechanistic understanding reported here can be utilized to control crystallographic features of colloidal assemblies, and may provide further insights into crystallographically preferred growth in synthetic, biological, and geological crystals.

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Convenient and Efficient Fabrication of Colloidal Crystals Based on Solidification-Induced Colloidal Assembly

Nanomaterials ◽

10.3390/nano9040575 ◽

2019 ◽

Vol 9 (4) ◽

pp. 575 ◽

Cited By ~ 2

Author(s):

Ting Shao ◽

Laixi Sun ◽

Chun Yang ◽

Xin Ye ◽

Shufan Chen ◽

...

Keyword(s):

Driving Force ◽

Crystallization Process ◽

Colloidal Crystal ◽

Colloidal Crystals ◽

Magnetic Interaction ◽

Colloidal Assembly ◽

Water Suspension ◽

Colloidal Crystallization ◽

New Strategy ◽

Crystal Grains

The simple yet efficient and versatile fabrication of colloidal crystals was investigated based on the solidification-induced colloidal crystallization process with particle/water suspension as precursor. The resulting colloidal crystals were constituted by crystal grains with sizes ranging from several tens of micrometers to a few millimeters. Each of the grains had a close-hexagonal array of colloids, which endowed the bulk colloidal crystal powders with some specific optical properties. The freezing of water was shown as the major driving force to form colloidal crystal grains, which supersaturated the solution with nanoparticles and thus induced the formation and growth of colloidal crystal seeds. This process is intrinsically different from those conventional methods based on shearing force, surface tension, columbic interaction or magnetic interaction, revealing a new strategy to fabricate colloidal crystals in a convenient and efficient way.

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Fabrication of large-area face-centered-cubic hard-sphere colloidal crystals by shear alignment

Physical Review E ◽

10.1103/physreve.61.2929 ◽

2000 ◽

Vol 61 (3) ◽

pp. 2929-2935 ◽

Cited By ~ 133

Author(s):

R. Amos ◽

J. Rarity ◽

P. Tapster ◽

T. Shepherd ◽

S. Kitson

Keyword(s):

Hard Sphere ◽

Colloidal Crystals ◽

Face Centered Cubic ◽

Large Area ◽

Shear Alignment ◽

Face Centered

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Solvent Engineering of the Precursor Solution toward Large‐Area Production of Perovskite Solar Cells

Advanced Materials ◽

10.1002/adma.202005410 ◽

2021 ◽

Vol 33 (14) ◽

pp. 2005410

Author(s):

Lingfeng Chao ◽

Tingting Niu ◽

Weiyin Gao ◽

Chenxin Ran ◽

Lin Song ◽

...

Keyword(s):

Solar Cells ◽

Perovskite Solar Cells ◽

Precursor Solution ◽

Large Area ◽

Solvent Engineering

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Polycrystal Simulation of Texture-Induced Grain Coarsening during Severe Plastic Deformation

Materials ◽

10.3390/ma13245834 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5834

Author(s):

Chi Zhang ◽

Laszlo S. Toth

Keyword(s):

Plastic Deformation ◽

Severe Plastic Deformation ◽

Electron Backscatter Diffraction ◽

Texture Evolution ◽

Face Centered Cubic ◽

Shear Texture ◽

Grain Coarsening ◽

Random Texture ◽

Polycrystal Plasticity ◽

Grain Fragmentation

During severe plastic deformation (SPD), there is usually extended grain fragmentation, associated with the formation of a crystallographic texture. The effect of texture evolution is, however, coarsening in grain size, as neighbor grains might coalesce into one grain by approaching the same ideal orientation. This work investigates the texture-induced grain coarsening effect in face-centered cubic polycrystals during simple shear, in 3D topology. The 3D polycrystal aggregate was constructed using a cellular automaton model with periodic boundary conditions. The grains constituting the polycrystal were assigned to orientations, which were updated using the Taylor polycrystal plasticity approach. At the end of plastic straining, a grain detection procedure (similar to the one in electron backscatter diffraction, but in 3D) was applied to detect if the orientation difference between neighboring grains decreased below a small critical value (5°). Three types of initial textures were considered in the simulations: shear texture, random texture, and cube-type texture. The most affected case was the further shearing of an initially already shear texture: nearly 40% of the initial volume was concerned by the coalescence effect at a shear strain of 4. The coarsening was less in the initial random texture (~30%) and the smallest in the cube-type texture (~20%). The number of neighboring grains coalescing into one grain went up to 12. It is concluded that the texture-induced coarsening effect in SPD processing cannot be ignored and should be taken into account in the grain fragmentation process.

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An Sem/Ebsd Study of Shear Bands Formation in Al-0.23%wt.Zr Alloy Deformed in Plane Strain Compression / Krystalograficzne Aspekty Formowania Sie Pasm Scinania W Stopie Al-0.23%Wag.Zr Odkształcanym W Próbie Nieswobodnego Sciskania

Archives of Metallurgy and Materials ◽

10.2478/v10172-012-0165-6 ◽

2013 ◽

Vol 58 (1) ◽

pp. 145-150 ◽

Cited By ~ 2

Author(s):

H. Paul ◽

P. Uliasz ◽

M. Miszczyk ◽

W. Skuza ◽

T. Knych

Keyword(s):

Crystal Lattice ◽

Grain Boundaries ◽

Texture Evolution ◽

Shear Bands ◽

Shear Direction ◽

Face Centered Cubic ◽

Electron Backscattered Diffraction ◽

Cubic Metals ◽

Slip Planes ◽

Face Centered

The crystal lattice rotations induced by shear bands formation have been examined in order to investigate the influence of grain boundaries on slip propagation and the resulting texture evolution. The issue was analysed on Al-0.23wt.%Zr alloy as a representative of face centered cubic metals with medium-to-high stacking fault energy. After solidification, the microstructure of the alloy was composed of flat, twin-oriented, large grains. The samples were cut-off from the as-cast ingot in such a way that the twinning planes were situated almost parallel to the compression plane. The samples were then deformed at 77K in channel-die up to strains of 0.69. To correlate the substructure with the slip patterns, the deformed specimens were examined by SEM equipped with a field emission gun and electron backscattered diffraction facilities. Microtexture measurements showed that strictly defined crystal lattice re-orientations occurred in the sample volumes situated within the area of the broad macroscopic shear bands (MSB), although the grains initially had quite different crystallographic orientations. Independently of the grain orientation, their crystal lattice rotated in such a way that one of the f111g slip planes became nearly parallel to the plane of maximum shear. This facilitates the slip propagation across the grain boundaries along the shear direction without any visible variation in the slip plane. A natural consequence of this rotation is the formation of specific MSB microtextures which facilitates slip propagation across grain boundaries.

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Li4Mn5O12 Lithium Ion Sieve Preparation and Adsorption Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1004-1005.670 ◽

2014 ◽

Vol 1004-1005 ◽

pp. 670-674 ◽

Cited By ~ 1

Author(s):

Dian Quan Dong ◽

Hong Bo Dai ◽

Jian Guo Zheng

Keyword(s):

High Selectivity ◽

Colloidal Crystal ◽

Average Pore Size ◽

Three Dimensional ◽

Lithium Ion ◽

Precursor Solution ◽

Exchange Capacity ◽

Average Pore ◽

Exchange Performance ◽

Roasting Condition

Polystyrene microspheres with 120nm diameter were synthesized by emulsion polymerization and three-dimensionally ordered colloidal crystal templates were obtained by centrifugal sedimentation.Three dimensionally ordered nanopore (3DON) manganese oxide lithium ion-sieve was prepared after filtration, two heated roasting and acid modified by using precursor solution filling the colloidal crystal templates, which was prepared by Lithium salt, manganese salt and citric acid. SEM, XRD, and saturated exchange capacity test were used to characterize the roasting condition, appearance, structure, and ion exchange performance of the oxide. The results showed that, the optimum roasting condition of preparing lithium ion-sieve precursors were found as follows: heating rate at 2°C/min, 300 °C roasting 4h and 800 °C roasting 8h, The 3DON Li4Mn5O12lithium ion sieve precursor has the shape of three-dimensional cross-linked connected into the network structure. Li4Mn5O12was regularly arranged and the hole wall was integrity,average pore size of approximately 90nm.3DON Li4Mn5O12 showed good stability for acid and the retrofit of lithium ion-sieve showed a high selectivity for Li+. The saturated exchange capacity of Li+is 51.98mgLi+/g.

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Synthesis of magnetic mesoporous titania colloidal crystals through evaporation induced self-assembly in emulsion as effective and recyclable photocatalysts

Physical Chemistry Chemical Physics ◽

10.1039/c5cp05005g ◽

2015 ◽

Vol 17 (41) ◽

pp. 27653-27657 ◽

Cited By ~ 18

Author(s):

Jeffrey E. Chen ◽

Hong-Yuan Lian ◽

Saikat Dutta ◽

Saad M. Alshehri ◽

Yusuke Yamauchi ◽

...

Keyword(s):

Crystal Structure ◽

Magnetic Properties ◽

Self Assembly ◽

Colloidal Crystal ◽

Colloidal Crystals ◽

Mesoporous Titania ◽

Evaporation Induced Self Assembly

This study illustrates the directed self-assembly of mesoporous TiO2 with magnetic properties due to its colloidal crystal structure with Fe3O4.

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Mixed-order phase transition in a colloidal crystal

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1712584114 ◽

2017 ◽

Vol 114 (49) ◽

pp. 12906-12909 ◽

Cited By ~ 10

Author(s):

Ricard Alert ◽

Pietro Tierno ◽

Jaume Casademunt

Keyword(s):

Phase Transition ◽

Phase Transitions ◽

Colloidal Particles ◽

Colloidal Crystal ◽

Equilibrium Phase ◽

Mean Field ◽

Critical Dimension ◽

Colloidal System ◽

Test Bed ◽

Mixed Order

Mixed-order phase transitions display a discontinuity in the order parameter like first-order transitions yet feature critical behavior like second-order transitions. Such transitions have been predicted for a broad range of equilibrium and nonequilibrium systems, but their experimental observation has remained elusive. Here, we analytically predict and experimentally realize a mixed-order equilibrium phase transition. Specifically, a discontinuous solid–solid transition in a 2D crystal of paramagnetic colloidal particles is induced by a magnetic field H. At the transition field Hs, the energy landscape of the system becomes completely flat, which causes diverging fluctuations and correlation length ξ∝|H2−Hs2|−1/2. Mean-field critical exponents are predicted, since the upper critical dimension of the transition is du=2. Our colloidal system provides an experimental test bed to probe the unconventional properties of mixed-order phase transitions.

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