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

Colloidal crystals (opals) made of close-packed polymethylmethacrylate (PMMA) were fabricated and grown by Template-Directed methods to obtain porous materials with well-ordered periodicity and interconnected pore systems to manufacture photonic crystals. Opals were made from aqueous suspensions of monodisperse PMMA spheres with diameters between 280 and 415 nm. SEM confirmed the PMMA spheres crystallized uniformly in a face-centered cubic (FCC) array. Optical properties of synthesized pores PMMA were characterized by UV–Visible spectroscopy. It shows that the colloidal crystals possess pseudo photonic band gaps in the visible region. A combination of Bragg’s law of diffraction and Snell’s law of refraction were used to calculate the sphere diameter. Finally, colloidal crystals were subjected to Z-scan experiment under pulsed Q-switched Nd:YAG laser illumination to characterize it for third order nonlinear optical properties. Z-scan results show the change in transmittance of a beam, and the nonlinear refractive index is n2 = 9.82787 x 10-12 (cm2/GW), while the nonlinear absorption coefficient β= 0.04673908 (cm/GW). These results were attributed to enhance the self-focusing arising from Kerr effect and the two-photon absorption.

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Slanted stacking faults and persistent face centered cubic crystal growth in sedimentary colloidal hard sphere crystals

CrystEngComm ◽

10.1039/c0ce00022a ◽

2010 ◽

Vol 12 (11) ◽

pp. 3820 ◽

Cited By ~ 12

Author(s):

Jan Hilhorst ◽

Joost R. Wolters ◽

Andrei V. Petukhov

Keyword(s):

Crystal Growth ◽

Hard Sphere ◽

Stacking Faults ◽

Face Centered Cubic ◽

Cubic Crystal ◽

Face Centered

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Template-directed convective assembly of three-dimensional face-centered-cubic colloidal crystals

Applied Physics Letters ◽

10.1063/1.1516614 ◽

2002 ◽

Vol 81 (17) ◽

pp. 3176-3178 ◽

Cited By ~ 35

Author(s):

J. Zhang ◽

A. Alsayed ◽

K. H. Lin ◽

S. Sanyal ◽

F. Zhang ◽

...

Keyword(s):

Three Dimensional ◽

Colloidal Crystals ◽

Face Centered Cubic ◽

Convective Assembly ◽

Face Centered ◽

Dimensional Face

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Deformation Twinning of Molecular Dynamics Simulation in a Ternary Titanium Alloy under Nanoindentation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.874.328 ◽

2016 ◽

Vol 874 ◽

pp. 328-332

Author(s):

Si Ling Huang ◽

Zhen Yu Zhang ◽

Jun Feng Cui ◽

Song Yang ◽

Xiao Guang Guo

Keyword(s):

Molecular Dynamics ◽

Single Crystal ◽

Md Simulations ◽

Deformation Twinning ◽

Dynamics Simulation ◽

Single Element ◽

Face Centered Cubic ◽

Ti Alloy ◽

Large Area ◽

Face Centered

Nanotwinned (nt) metals exhibit excellent mechanical, electrical and thermal properties, and therefore attract much attentions. To fabricate large area nt surface, the fundamental mechanisms of deformation twinning induced by molecular dynamics (MD) are necessary to be explored. Nevertheless, MD of nt metals currently focus mainly on nt copper (Cu) and other single element metals with face-centered cubic (fcc) structure. In addition, MD simulations are usually performed on a built nt model, rather than from a single crystal, due to the difficulty of forming nanotwins. In this study, a single crystal is constructed in a ternary titanium (Ti) alloy with hexagonal closed-packed (hcp) lattice cell. Deformation twinning of MD simulation is performed in a ternary Ti alloy under nanoindentation from the built single crystal. Zonal structure is found during loading under nanoindentation, and nanograins transforms into nanotwins. Deformation twinning is significant to understanding the formation of nanotwins, as well as fabricating large area nt surface on a Ti alloy.

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Large Area C60 Film Obtained by Microwave Oven Irradiation from an Organic Resin

ISRN Nanomaterials ◽

10.1155/2013/524548 ◽

2013 ◽

Vol 2013 ◽

pp. 1-5 ◽

Cited By ~ 3

Author(s):

J. Martínez-Reyes ◽

L. G. Díaz Barriga-Arceo ◽

L. Rendón-Vazquez ◽

R. Martínez-Guerrero ◽

N. Romero-Parada ◽

...

Keyword(s):

Electron Microscopy ◽

Microwave Oven ◽

Lattice Parameters ◽

Main Phase ◽

Crystal Habit ◽

Face Centered Cubic ◽

Large Area ◽

Monoclinic System ◽

Cubic Structure ◽

Face Centered

In the present work the synthesis of fullerene thin film produced in a conventional microwave oven from the decomposition of terpenoid is reported. The polycrystalline structure of the sample was determined by X-ray diffraction (XRD); the sample showed several phases, and the main phase corresponds to fullerene ordered in a face-centered cubic structure (FCC), with a lattice parameter a=14.16 Å, with two more structures: one is orthorhombic system with lattice parameters a=9.53 Å, b=8.87 Å, and c=8.354 Å, and the other is the monoclinic system with lattice parameters a=10.24 Å, b=7.80 Å, c=9.49 Å, and β=92.4° coexisting also with graphite 2H phase with lattice parameters a=2.46 Å, c=6.71 Å. It was observed in a scanning electron microscopy (SEM) that the sample formed thin films of stacked carbon. The film thickness was measured by a SEM, and it was 140.8 to 523 nm and the macroscopic area of 12 cm2, whereas a high-resolution transmission electron microscopy (HRTEM) revealed that the main phase of the material is C60 ordered in a face-centered cubic structure (FCC). In the sample surface by atomic force microscopy (AFM), islands deposited crystals were observed having symmetry 4-3m crystal habit associated with the tetrahedron.

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Fabricación y caracterización óptica de cristales coloidales de alta calidad formados por esferas de SiO2 de 225 nm de diámetro con empaquetamiento fcc crecidos por el método convectivo de auto-ensamblado de deposición vertical.

Universitas Scientiarum ◽

10.11144/javeriana.sc15-2.faoc ◽

2010 ◽

Vol 15 (2) ◽

pp. 150 ◽

Cited By ~ 3

Author(s):

Octavio Alejandro Castañeda-Uribe ◽

Juan Carlos Salcedo-Reyes ◽

Henry Alberto Méndez-Pinzón ◽

Aura Marina Pedroza-Rodríguez

Keyword(s):

Photonic Crystals ◽

Self Assembly ◽

Volume Fraction ◽

Colloidal Crystals ◽

Optical Characterization ◽

Bragg Diffraction ◽

Face Centered Cubic ◽

High Quality ◽

Assembly Method ◽

Face Centered

Objective: Fabrication and optical characterization of close-packed 225 nm SiO2 -based colloidal crystals. Materials and methods: The vertical convective self-assembly method is used to grow high-quality 225 nm close-packed SiO2-based colloidal crystals. An annealing process (550°C) is made in order to improve the mechanical stability of the sample. Optical characterization is done by angle-resolved transmission spectroscopy (A-RTS) and structural characterization by Scanning Electron Microscopy (SEM). Results: Both, A-RTS and SEM, show that with the vertical convective self-assembly method, with the appropriate parameters of temperature of evaporation (60°C), volume fraction of the colloidal suspension (0.2% w/w) and acidity (pH=6), highly ordered close packed face centered cubic (fcc) SiO2 based colloidal crystals are obtained. Conclusions: The growth of high-quality (long range order and defect-free) face centered cubic opal-based photonic crystals is reported. Key words: Photonic crystals, colloidal crystals, artificial opals, vertical convective deposition method, Bragg diffraction

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Poisson’s Ratio of the f.c.c. Hard Sphere Crystals with Periodically Stacked (001)-Nanolayers of Hard Spheres of Another Diameter

Materials ◽

10.3390/ma12050700 ◽

2019 ◽

Vol 12 (5) ◽

pp. 700 ◽

Cited By ~ 4

Author(s):

Jakub Narojczyk ◽

Krzysztof Wojciechowski

Keyword(s):

Poisson’S Ratio ◽

Hard Sphere ◽

High Pressures ◽

Hard Spheres ◽

Poisson's Ratio ◽

Face Centered Cubic ◽

The Matrix ◽

The Face ◽

Face Centered ◽

Maximal Average

The results of studies on the influence of periodically stacked nanolayer inclusions, introduced into the face-centered cubic (f.c.c.) hard sphere crystal, on Poisson’s ratio of the obtained nanocomposite system are presented. The monolayers are orthogonal to the [ 001 ] -direction. They are formed by hard spheres with diameter different from the spheres forming the matrix of the system. The Monte Carlo computer simulations show that in such a case the symmetry of the system changes from the cubic to tetragonal one. When the diameter of the inclusion spheres increases at certain range, a decrease of the negative Poisson’s ratio in the [ 101 ] [ 1 ¯ 01 ] -directions is observed, i.e., the system enhances its partial auxeticity. The dependence of the maximal, average, and negative parts of the minimal Poisson’s ratio on the direction of the applied load are shown in a form of surfaces in spherical coordinates, plotted for selected values of nanolayer particle diameters. The most negative value of the Poisson’s ratio found among all studied systems was − 0.11 (at pressure p * = 100 , which is about ten times higher than the melting pressure) what is almost twice more negative than in the f.c.c. crystal of identical hard spheres. The observed effect weakens along with the decrease of pressure and becomes hardly noticeable near melting. This study indicates that modifying only the size of the inclusion particles one can change Poisson’s ratio of nanocomposites at high pressures.

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2107588118 ◽

2021 ◽

Vol 118 (32) ◽

pp. e2107588118

Author(s):

Ling Li ◽

Carl Goodrich ◽

Haizhao Yang ◽

Katherine R. Phillips ◽

Zian Jia ◽

...

Keyword(s):

Colloidal Particles ◽

Colloidal Crystal ◽

Texture Evolution ◽

Colloidal Crystals ◽

Continuum Theory ◽

Precursor Solution ◽

Crystal Structure Analysis ◽

Face Centered Cubic ◽

Large Area ◽

Colloidal Assembly

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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