Three-dimensional Crystalline Research Articles

A general photonic crystal sensing motif: creatinine in bodily fluids.

We developed a new sensing motif for the detection and quantification of creatinine, which is an important small molecule marker of renal dysfunction. This novel sensor motif is based on our intelligent polymerized crystalline colloidal array (IPCCA) materials, in which a three-dimensional crystalline colloidal array (CCA) of monodisperse, highly charged polystyrene latex particles are polymerized within lightly cross-linked polyacrylamide hydrogels. These composite hydrogels are photonic crystals in which the embedded CCA diffracts visible light and appears intensely colored. Volume phase transitions of the hydrogel cause changes in the CCA lattice spacings which change the diffracted wavelength of light. We functionalized the hydrogel with two coupled recognition modules, a creatinine deiminase (CD) enzyme and a 2-nitrophenol (2NPh) titrating group. Creatinine within the gel is rapidly hydrolyzed by the CD enzyme in a reaction which releases OH(-). This elevates the steady-state pH within the hydrogel as compared to the exterior solution. In response, the 2NPh is deprotonated. The increased solubility of the phenolate species as compared to that of the neutral phenols causes a hydrogel swelling which red-shifts the IPCCA diffraction. This photonic crystal IPCCA senses physiologically relevant creatinine levels, with a detection limit of 6 microM, at physiological pH and salinity. This sensor also determines physiological levels of creatinine in human blood serum samples. This sensing technology platform is quite general. It may be used to fabricate photonic crystal sensors for any species for which there exists an enzyme which catalyzes it to release H(+) or OH(-).

Smectic blue phases: layered systems with high intrinsic curvature.

We report on a construction for smectic blue phases, which have quasi-long-range smectic translational order as well as three-dimensional crystalline order. Our proposed structures fill space by adding layers on top of a minimal surface, introducing either curvature or edge defects as necessary. We find that for the right range of material parameters, the favorable saddle-splay energy of these structures can stabilize them against uniform layered structures. We also consider the nature of curvature frustration between mean curvature and saddle splay.

Some novel three-dimensional Euclidean crystalline networks derived from two-dimensional hyperbolic tilings

We demonstrate the usefulness of two-dimensional hyperbolic geometry as a tool to generate three-dimensional Euclidean (E3) networks. The technique involves projection of edges of tilings of the hyperbolic plane (H2) onto three-periodic minimal surfaces, embedded in E3. Given the extraordinary wealth of symmetries commensurate with H2, we can generate networks in E3 that are difficult to construct otherwise. In particular, we form four-, five- and seven-connected (E3) nets containing three- and five-rings, viz. (3, 7), (5, 4) and (5, 5) tilings in H2.

Stability of Crystalline Ion Beams

In this paper, the conditions for which three-dimensional crystalline ion beams were attained in the rf quadrupole storage ring PALLAS at a velocity of around 2800 m/s are presented. The stability of these crystalline beams when subjected to discontinuous cooling is discussed for beams of different linear density and thus of different crystal structure. The survival time seems to only weakly depend on the linear density, in contrast to the heating of the beam after melting.

Fabrication of Inverse Opal via Ordered Highly Charged Colloidal Spheres

A new and simple procedure for producing highly ordered three-dimensional colloidal crystalline template was developed, which employs latexes containing highly charged polystyrene spheres. The water on the surface of the latex was evaporated, causing the formation of close-packed colloidal crystals on the surface. The driving forces for the formation of close-packed crystal involve electrostatic interaction and lateral capillary force, and the ion diffusion during the evaporation is considered to be an important factor for the successful assembly of ordered structure on the latex surface. Then the sol−gel solution was infiltrated into the interstitial space of the prepared colloidal crystals through capillary effect, and ordered inverse opals were obtained by calcining the polystyrene beads. The inverse opal thus prepared has long-range ordering with its defect-free area extending to over 10 micrometers and covering thousands of pores.

Three-dimensional crystalline ion beams.

We report on the experimental realization of two- and three-dimensional crystalline ion beams in the rf quadrupole storage ring PALLAS (LMU, Munich). At a beam energy around 1 eV the phase transition to the Coulomb ordered state is identified by a sudden decrease of the spatial width and of the velocity spread of the beam. The focusing conditions required to attain crystalline beams up to structures of helices surrounding a string are systematically investigated and related to the situation in typical heavy ion storage rings.

Growth of Isolated Three-Dimensional Crystalline Nuclei in a Mixed Kinetics Mode

For the case of the mixed kinetics, equations are derived for the time dependences of the nucleus size and current at N isolated nuclei, which account for the initial stage of the nucleus growth. Approximating formulas describing the system behavior at various time instants and containing equations for the diffusion and kinetic modes as specific cases are obtained.

Infrared spectra of 1-monopalmitin- or 1-monostearin-water systems in the gel phase

The infrared spectra of 1-monopalmitin- or 1-monostearin-water systems in the gel phase were observed at room temperature. In both systems the infrared intensities of the bands parallel and perpendicular to the paraffin chain are relatively reduced and enhanced, respectively, on going from the crystalline phase to the gel phase. These spectral changes are explained in terms of the interaction among oscillating dipoles, which is sensitive to the morphology change from the three-dimensional crystalline phase to the two-dimensional lipid bilayers. The non-planar lipid bilayers are proposed for the gel phase in monopalmitin-water systems with x⩾35 ( x: wt.% water).

Structural Transformations in Three-Dimensional Crystalline GeSe2 at High Pressures and High Temperatures

Germanium diselenide GeSe2 is studied in situ at the pressure range 2–6 GPa using angle-dispersive X-ray diffraction in a large volume Paris–Edinburgh cell. The structure at 2 GPa and 698 K, solved with direct methods in the I4 space group (a=5.5073(3) Å, c=9.9374(8) Å, Z=4), is three dimensional with all the GeSe4 tetrahedra sharing their corners. Anomalous lattice expansion along the c axis with increasing pressure and pressure-induced structural variations are explained by anisotropic lattice distortions due to cooperative tiltings of the rigid GeSe4 units.

Mass Determination of the Unit Cell of the Innermost Chorionic Layer in Drosophilidae by Scanning Transmission Electron Microscopy

The innermost chorionic layer (ICL) in eggshells of Drosophila melanogaster is a naturally occurring patchwork of thin three-dimensional crystalline plates located between the inner endochorion and the vitelline envelope. The mass-per-unit area of the ICL has been measured from scanning transmission electron microscope images of isolated unstained material and it was possible to distinguish up to four layers with the majority of the crystalline sheets being one to three layers thick. Taking into account the unit cell areas for the different crystals, we have estimated the mean ICL subunit sizes to be 36 kDa for Drosophila melanogaster, 35 kDa for Drosophila auraria, and 33 kDa for Drosophila teissieri. The results suggest that the three different Drosophilidae species have very similar average subunit masses.

Possible nonlinear heat-pulse propagation in solids at Debye temperatures

Molecular dynamics techniques are used to show that heat can be transferred ballistically in threedimensional crystalline materials at temperatures on the order of Debye temperatures.

The Microassembly Technique for a 3D Single Crystalline Silicon Structure Using a Polyimide/Chromium Cantilever

The microassembly technique on the wafer is key technology to realize multi-axis sensors (e. g. magnetometer) or three-dimensional micro systems (e. g. an optical system). We have investigated the bending of a polyimide/chromium cantilever to lift a silicon island (400×300×10μm3 and 1000×1000×240μm3) on the wafer at an angle of 90°, the planarization of a diced silicon sidewall and the bonding of a silicon island to the planarized silicon sidewall with polyimide interlayer. With this microassembly technique, the three-dimensional single crystalline silicon structures have been fabricated.

Heterophase quasicrystalline interfaces and their characterization

Abstract The characterization of heterophase interfaces in icosahedrally related systems cannot be accomplished by the available three-dimensional crystalline terms owing to lack of periodicity of at least one of the phases constituting the boundary. The purpose of this communication is to show that the existing method of interface characterization in terms of registry of the two underlying lattices can be recovered for quasiperiodic cases by extending the concept to six- dimensional hyperspace. This has been demonstrated by the method of characterizing the interface between icosahedral and decagonal quasicrystals found in Al-Pd-Mn system.

Heterophase quasicrystalline interfaces and their characterization

Abstract The characterization of heterophase interfaces in icosahedrally related systems cannot be accomplished by the available three-dimensional crystalline terms owing to lack of periodicity of at least one of the phases constituting the boundary. The purpose of this communication is to show that the existing method of interface characterization in terms of registry of the two underlying lattices can be recovered for quasiperiodic cases by extending the concept to six- dimensional hyperspace. This has been demonstrated by the method of characterizing the interface between icosahedral and decagonal quasicrystals found in Al-Pd-Mn system.

EPR spectroscopy of low-dimension structures produced in natural diamonds and synthetic diamond films by ion implantation (review)

We give a brief overview of the results of investigations that gave birth to new trends in radiospectroscopy, physics of interactions of atomic particles with condensed materials, and solid-state physics, especially, physics of superhard materials. The main factors that provided the basis for these trends are as follows. 1. High-energy ion implantation into solids plays a constructive role with respect to the solid matrix. A modified structure composed of matrix atoms and characterized by both short-range and long-range orders different from the initial one is formed as a result of this implantation. Low-dimension systems of a new class, whose properties are described in the present work, were produced in diamonds. A distinguishing feature of this new class of elements is that one-dimensional elements possesing their own spatial ordering of atoms constitute a volume superlattice composed of the same atoms in a three-dimensional crystalline matrix. 2. Radiospectroscopy methods can be used to identify formations with sizes greater than 0.1 μm in one dimension (along with traditional objects with sizes within the nanorange in three dimensions) and study their properties. These objects are characterized by a number of essentially new radiospectroscopic properties: superlinear kinetics of resonance absorption, an additional nonzero phase angle in the recorded absorption signal relative to the hf modulation field in the absence of saturation, (“phase angle”), an anomalous increase in the intensity of absorption with an increase in the modulation frequency of the static field (in the absence of saturation), and a super-Lorentizian shape of the resonance absorption line. These properties provide a basis for radiospectroscopic identification of mobile quasiparticles with nonzero spin (like to solitons) in solids. 3. A system of “channels” with high electroconductivity (in the microwave range) can be produced in dielectric solids, specifically in superhard materials. Individual channels can have cross-sectional sizes of up to sizes of the nanorange. This can serve as a basis for the development of electronic devices with elements having cross-sectional sizes that are significantly smaller than those of elements of traditional microelectronics as small as the sizes of elements of nanotechnology.

Crystal Structures of Monodisperse Colloidal Silica in Poly(methyl acrylate) Films

Dispersions of 22.3 vol % of 153 nm diameter silica particles coated with 3-(trimethoxysilyl)propyl methacrylate in liquid methyl acrylate (MA) as 264−528 μm thick films in glass cells spontaneously order into colloidal crystals and Bragg diffract visible light from lattice planes parallel to the film plane. Photopolymerization of the MA gives elastomeric poly(methyl acrylate) (PMA) films with retention of the crystalline order. Swelling the films with more MA and further polymerization give colloidal crystalline composite films with larger lattice spacings. The crystal structures are modeled as face centered cubic for the monomer dispersions and rhombohedral for the polymer films. Layer spacings observed in scanning electron micrographs (SEM) of microtomed PMA films are used to calculate the (111) spacings and the lattice parameter a of the model. The layer spacings correlate well with the diffraction wavelengths from optical spectra. Ultrasmall angle X-ray diffraction also was performed to demonstrate the three-dimensional crystalline order. The SEM and optical spectra also fit hexagonal close packed (hcp) or mixed rhombohedral and hcp structures.

Phason-strain analysis of the twinned approximant to the decagonal quasicrystalAl70Co15Ni15: Evidence for a one-dimensional quasicrystal

In high-resolution x-ray diffraction sometimes a pronounced splitting of the strongest Bragg reflections in decagonal ${\mathrm{Al}}_{70}$ ${\mathrm{Co}}_{15}$ ${\mathrm{Ni}}_{15}$ is observed. So far, this has been interpreted as evidence for a twinned (micro-)crystalline state with large lattice parameters. In the present paper we show that the metrics can be perfectly reproduced by modeling a twinned one-dimensional quasicrystal rather than a twinned three-dimensional crystalline phase. The split peak positions can easily be reproduced by application of a linear phason strain on the ideal decagonal quasicrystal and subsequent fivefold twinning. New high-resolution x-ray-diffraction data are used in this analysis. An anisotropic broadening of all investigated reflections leads us to suggest a nonlinear phason-strain component.

Large and stable second harmonic generation in a crystalline phase of a ferroelectric liquid crystal

Second harmonic generation (SHG) has been studied in a nitro-substituted ferroelectric liquid crystal cooled from the smectic-C* into a three-dimensional crystalline (K) phase in an applied electric field. The SHG efficiency in the K phase is found to be deff≳4.5 pm/V, about 25 times the value in the SmC* phase, and, unlike the SmC* case, remains constant in zero field for ≳25 h. A quantitative analysis of the polarization dependence of the SHG reveals that the dominant d coefficients contributing to the measured signal differ for the two phases, and that the orientation of the liquid-crystal director in the K phase is modulated in one dimension.

Ultrathin layers and supramolecular architecture of isopentylcellulose

The characterization of multilayers from tri-O-isopentyl cellulose assembled by the Langmuir-Blodgett technique is described. The analysis of ultrathin films by X-ray reflection confirmed a homogeneous overall film quality but did not show any Bragg reflection. However, investigation of a superstructure in terms of an alternating multilayer sample from deuterated and nondeuterated isopentylcellulose ethers by neutron reflection revealed a perfectly periodic layer structure. The influence of the degree of substitution of the isopentylcellulose ethers on the formation and structure of multilayers was investigated as well. Multilayers of partially substituted isopentylcellulose exhibit a periodical film structure composed of double layers. The perfection of the films is not influenced by the residual OH functions. The in-plane structure of tri-O-isopentylcellulose multilayers was investigated by electron diffraction in transmission geometry. The cellulose ether forms a helix of 3-fold symmetry, and the helix axes are preferentially oriented parallel to the dipping direction. Upon annealing a three-dimensional crystalline film of layered structure is obtained in which the chains are packed in a monoclinic unit cell. The very small diameter of the cellulose derivatives of less than 10 A/molecule in the layered superstructures and the observation that very perfect and homogeneously oriented multilayers are obtained by the Langmuir-Blodgett technique augment the toolbox of molecular architects interested in the rational construction of supramolecular architectures.

Phonon-induced nonmetal-metal transition of a doped polyaniline

We report the crossover for the microwave dielectric constant of camphor-sulfonic-acid-doped polyaniline prepared in m-cresol from very large room-temperature negative values to large positive ones with decreasing temperature below ${\mathit{T}}_{\mathit{s}}$\ensuremath{\sim}20 K. We attribute this change to the transition from a phonon-controlled metallic state to a nonmetallic state with localized carriers and hopping transport below ${\mathit{T}}_{\mathit{s}}$. Electronically, one-dimensional chains that couple the three-dimensional crystalline regions are likely central for understanding the origin of this transition as weak localization. At T${\mathit{T}}_{\mathit{s}}$ we also observed an increase in the thermoelectric power and a linear decrease in the reduced activation energy for dc conductivity.