A. A. Mistonov

Fabrication of artificial opals by electric-field-assisted vertical deposition.

We present a new technique for large-scale fabrication of colloidal crystals with controllable quality and thickness. The method is based on vertical deposition in the presence of a DC electric field normal to the conducting substrate. The crystal structure and quality are quantitatively characterized by microradian X-ray diffraction, scanning electron microscopy, and optical reflectometry. Attraction between the charged colloidal spheres and the substrate promotes growth of thicker crystalline films, while the best-quality crystals are formed in the presence of repulsion. Highly ordered thick crystalline layers with a small amount of stacking faults and a low mosaic spread can be obtained by optimizing the growth conditions.

Determination of the real structure of artificial and natural opals on the basis of three-dimensional reconstructions of reciprocal space

The distribution of the scattering intensity in the reciprocal space for natural and artificial opals has been reconstructed from a set of small-angle X-ray diffraction patterns. The resulting three-dimensional intensity maps are used to analyze the defect structure of opals. The structure of artificial opals can be satisfactorily described in the Wilson probability model with the prevalence of layers in the fcc environment. The diffraction patterns observed for a natural opal confirm the presence of sufficiently long unequally occupied fcc domains.

Electric-Field-Assisted Self-Assembly of Colloidal Particles

A method for formation of photonic crystals has been proposed. The method is based on convective deposition of colloidal particles onto vertical substrates in the presence of a direct-current electric field directed perpendicular to the surface of the formed film and an alternating-current electric field applied parallel to the substrate plane. The structure and optical properties of the prepared colloidal crystals have been investigated using scanning electron microscopy, high resolution small-angle X-ray diffraction, and optical spectroscopy.

Ice rule for a ferromagnetic nanosite network on the face-centered cubic lattice

The magnetic properties of an inverse opal-like cobalt-based structure having the symmetry of the face-centered cubic lattice are studied. The magnetization reversal of the structure in a magnetic field applied along the [

DIRECT OBSERVATION OF THE SHELL-LIKE STRUCTURE OF SiO 2 PARTICLES SYNTHESIZED BY THE MULTISTAGE ST € OBER METHOD

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Temperature behavior of the local magnetization vectors in ferromagnetic inverted opal-like structures

] axis is described using a phenomenological model, which uses the ice rule for the local magnetization of nanostructure elements. This description predicts the absence of a long-range magnetic order in two <111> directions that are normal to the magnetic field. The magnetic structure is analyzed by smallangle neutron diffraction. Neutron diffraction patterns are measured in an external magnetic field varying from −1.2 to 1.2 T and applied along the crystallographic [

Small-angle X-ray diffraction investigation of twinned opal-like structures

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