Inorganic Crystalline Materials Research Articles

放射光Ｘ線回折法によるメタンフェタミン塩酸塩粉末中の微量不純物分析

Analysis of trace amounts of crystalline impurities such as sodium chloride (NaCl) and diacetylmorphine hydrochloride (heroin) in seized methamphetamine hydrochloride (MA·HCl) powders was carried out using synchrotron radiation X-ray diffraction (SR-XRD) at beam line BL19B2 in SPring-8 for the scientific drug investigation. The analytical results were compared with those obtained by the analysis method of using conventional XRD instrument. About one milligram of the MA·HCl powder was packed in a glass capillary tube with 0.3 mm inner diameter, and exposed to the monochromatic SR X-ray beam. The diffraction lines from the seized MA·HCl powder were detected and recorded using a imaging plate in a Debye Sherrer camera. The peak width at half height for the SR-XRD at BL19B2 was found to be about half of that for the conventional XRD. Therefore small diffraction lines from trace impurities could be clearly separated from the other lines from major components. Some sharp lines originating from trace amounts of heroin and NaCl in a milligram quantity of the seized MA·HCl samples could be confirmed using the SR-XRD, whereas these lines could not be identified clearly by the conventional XRD. The advantages of the SR-XRD are simultaneous detection of trace crystalline impurities, including both organic and inorganic materials, in small amounts of MA·HCl samples, and rapid analysis with high angle resolution. This method should be very effective for the discrimination of illicit MA·HCl samples containing trace impurities.

Development of inter- and intragranular stresses during switching of ferroelectric polycrystals

Ferroelectrics are crystalline inorganic materials consisting of domains with different directions of spontaneous polarization. By application of sufficiently high electric fields, these domains can switch into a common direction, thus making the material piezoelectric. Due to ferroelasticity, the domains can be also switched into different states by the application of mechanical stress. In polycrystalline materials, as used in most applications, electric and stress fields interact so as to maintain compatibility. We study the influence of grain-to-grain interactions on the overall and local switching behavior and in particular the induced stresses inside grains and across grain boundaries. The behavior inside each grain is represented by the single-crystal model of [Huber, J.E., Fleck, N.A., Landis, C.M., McMeeking, R.M., 1999. A constitutive model for ferroelectric polycrystals. Journal of the Mechanics and Physics of Solids 47 (8), 1663–1697] and the polycrystal response is obtained through a two-dimensional multi-grain model in which grains are represented individually. We investigate the effect of random grain orientations, both in the plane of consideration and in three directions, and compare plane strain with plane stress conditions. It is found that the overall piezoelectric response under electric loading is not dependent only on the intra- and intergranular stresses in the plane but is also significantly affected by stresses in through-thickness direction.

Thermotropic Mesomorphic Behavior of Surfactant-Encapsulated Polyoxometalate Hybrids

We investigate in detail novel organic-inorganic hybrid liquid crystalline materials, the complexes of surfactant-encapsulated polyoxometalate clusters (SECs), using thermal, X-ray diffraction, and FT-IR spectroscopic analyses. The differential scanning calorimetry measurements reveal four phase transitions under heating processes. We employ FT-IR spectroscopy to understand these phase behaviors. On the basis of vibration spectral assignments, the evidence suggests that the first two phase transitions are associated with the increase of gauche conformers and the disruption of alkyl chains packing in the heating run; the third phase transition is due to the full conformational disorder of alkyl chains covered on the polyoxometalates (PMs); no significant C-H stretching or wagging vibrations are observed with the fourth transition. We find that the fourth endothermic peak is sensitive to the charges of the PMs, and the transition temperature decreases from 185, 177, to 164 degrees C with decreasing PM charges from 13, 11, to 9, respectively. Interestingly, the temperatures of the first three phase transitions of SECs are essentially independent of the PM charges.

Recent progress in solid oxide and lithium ion conducting electrolytes research

Recent material developments of fast solid oxide and lithium ion conductors are reviewed. Special emphasis is placed on the correlation between the composition, structure, and electrical transport properties of perovskite-type, perovskite-related, and other inorganic crystalline materials in terms of the required functional properties for practical applications, such as fuel or hydrolysis cells and batteries. The discussed materials include Sr- and Mg-doped LaGaO3, Ba2In2O5, Bi4V2O11, RE-doped CeO2, (Li,La,)TiO3, Li3La3La3Nb2O12 (M=Nb, Ta), and Na super-ionic conductor-type phosphate. Critical problems with regard to the development of practically useful devices are discussed.

Block Copolymer Assemblies as Templates for the Generation of Mesoporous Inorganic Materials and Crystalline Films

AbstractThis Microreview presents the synthesis of mesoporous, crystalline inorganic materials using self‐assembled block copolymer mesostructures as templates. The advances in this field are discussed in light of the progress in the development of suitable polymer templates. Particular emphasis is placed on the special conditions and demands to transform the primary sol–gel films into mesoporous, aligned crystalline films for functional applications. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Design of Ruthenium Catalysts Bound to Inorganic Crystalline Materials for Environmentally-Benign Organic Synthesis

This article reviews a novel approach to design heterogeneous Ru catalysts using hydroxyapatites and hydrotalcites, and their excellent catalytic performances for aerobic alcohol oxidations, carbon-carbon bond formations, and one-pot syntheses. The catalytic systems using the above heterogeneous Ru catalysts offer significant benefits in achieving simple and clean organic syntheses. Furthermore, the present preparation method for the immobilization of metal species is much simpler than previous synthetic methods of the solid-supported transition metal catalysts, which can allow a strong protocol to create various nanostructured and functionalized heterogeneous metal catalysts.

Analysis of environmental particles by atomic force microscopy, scanning and transmission electron microscopy

Due to their large specific surface and their abundance, micro and nano particles play an important role in the transport of micropollutants in the environment. Natural particles are usually composed of a mixture of inorganic amorphous or crystalline material (mainly FeOOH, Fe(x)Oy, Mn(x)Oy and clays) and organic material (humics and polysaccharides). They all tend to occur as very small particles (1-1,000 nm in diameter). Most natural amorphous particles are unstable and tend to transform with time towards more crystalline forms, either by aging or possibly, by dissolution and re-crystallization. Such transformations affect the fate of sorbed micropollutants and the scavenging properties are therefore changed. As these entities are sensitive to dehydration (aggregation, changes in the morphology), it is highly important to observe their morphology in their natural environment and understand their composition at the scale of the individual particles. Also for the understanding and optimization of water treatment technologies, the knowledge of the occurrence and behavior of nano-particles is of high importance. Some of the possible particle analysis methods are presented: aggregation processes, biomineralization, bacterial adhesion, biofilms in freshwaters, ferrihydrite as heavy metals remover from storm water. These examples demonstrate the capabilities and focus of the microscopes. Atomic Force Microscopy (AFM) allows to analyze the particles in their own environment, meaning in air or in the water. Thus, native aspects of particles can be observed. As well, forces of interactions between particles or between particles and other surfaces such as membranes will be highly valuable data. Scanning Electron Microscopy (SEM) and for higher lateral resolution, Transmission Electron Microscopy (TEM) allow measurement of the morphology and composition. Especially, TEM coupled with Electron Energy Loss Spectroscopy (TEM-EELS) is a powerful technique for elemental analysis. Finally, general guidelines for the effective use of microscopic techniques are provided.

New class of indium-containing room temperature inorganic scintillators

In spite of intensive study during recent years, efficient room temperature operating inorganic crystalline scintillating materials based on indium were not mastered yet. These materials could be very important to eventually perform experiments for low-energy neutrinos detection. Here, we report on the scintillation properties of a class of indium containing scintillating materials: indium-based tungstates. The following materials have been investigated: LiIn(WO4)2, NaIn(WO4)2, In6WO12 and CaIn2O4, either pure or terbium-doped. These compounds were produced in the form of powder by solid-state synthesis. They were identified by X-ray diffraction as single-phase materials.Among studied materials, undoped NaIn(WO4)2, and LiIn(WO4)2 scintillators show the most promising scintillation characteristics at room temperature. Light yield of both materials was measured as about 30% of BGO. Emission maximum is located about 490nm.Scintillation decay is three-exponential with time constants of about 10, 100, and 500ns.Some of the other ternary indium oxides also show bright but slow scintillations when doped with terbium.

Measurement of the photorefractive space-charge field in a ferroelectric mesogen

We report on the measurement of the photorefractive space-charge field in a chiral smectic C mesophase. The liquid crystal is intrinsically photoconducting and undoped. The space-charge field amplitude, obtained from a model connecting the induced refractive index modulation with the electric fields within the medium, is only 1% of the applied field. Nonetheless, high refractive index modulations Δn∼10−3 can be obtained because of the high spontaneous birefringence of the mesophase. The use of the standard models for inorganic crystalline photorefractive materials would have given a space-charge field amplitude two orders of magnitude higher.

Melting behaviour in the n-alkanol family. Enthalpy–entropy compensation

The melting behaviour was studied in ten systems: C15OH–C16OH, C16OH–C17OH, C17OH–C18OH, C18OH–C19OH, C19OH–C20OH with Δn = 1 (difference in chain length), C15OH–C17OH, C16OH–C18OH, C17OH–C19OH, C18OH–C20OH with Δn = 2, and C16OH–C20OH with Δn = 4. The phase that melts is either the monoclinic R′IV(C2/m, Z = 4) or the hexagonal R′II(Rm, Z = 6) rotator form. One of the most important issues in the melting of these systems is that when the two original compounds of the system are isostructural, the phase diagram does not always show total miscibility. In the systems studied here, only the C15OH–C16OH, C18OH–C19OH and C19OH-C20OH systems show total miscibility. In the other systems in which the two original compounds are isostructural, miscibility is partial, as in the systems where the two original compounds are not isostructural. In this family, as in other families of mixed crystals, there is an excess enthalpy-entropy compensation. This compensation has a temperature dimension, and is called the compensation temperature (θ) of the family and/or subfamily. In the case of the R′II and R′IV rotator forms of the n-alkanols family its value is 362 K. This value is in line with the trend show by a large group of organic and inorganic mixed crystalline materials.

Electron Spectroscopic Tomography for Materials Science

Abstract Tomographic 3D-reconstructions from tilt series of projections differ in two major aspects when moving from biochemistry (e.g.) to materials science applications: (I) Crystalline inorganic materials fail the weak phase image formation approximation and suffer from dynamic and nonlinear contrast contributions (which depend for both CTEM and HREM on atomic lattice plane orientation). (II) exposure tolerance increases by two orders of magnitude. We therefore propose energy filtered tomography with inelastic electrons (electron spectroscopic imaging, ESI) as a new method for 3D-reconstruction of free or buried subsurface nanostructures or nanoparticles. Energy filters are not used here to improve SNR by removing inelastic background, but to provide the necessary projection relationship between a 3D concentration distribution and the (processed) image intensity. Ideally, a 4-dimensional data space is recorded for a single tilt axis tomography experiment, D=D(δE, Θ,x,y), (with 5E as energy loss, Θ as tilt, and (x,y) as image coordinates). The material has to withstand exposures of T = t × Ntilt × Nloss (t = 5...20sec per image, Ntilt >12 directions, Nloss = 5....20 energy loss values).

Local Dissipation Phenomena in Crystalline Forms of Boron

A classification is proposed for dissipation (in particular, relaxation) processes in crystalline systems and inorganic materials. The concepts of modifying and aggregation subsystems are defined. Relations are derived for determining the temperature dependences of the local “quasi-viscous” dissipation parameter r iand the local “quasi-elastic” parameter K ifor each relaxation transition in the tan δ(T) spectrum.

Auxetic behavior from rotating squares

Auxetic materials exhibit the very unusual properties of becoming wider when stretched and narrower when squashed [1], that is they have negative Poisson’s ratios. Apart from the pure scientific interest of having materials showing such an unconventional property, a negative Poisson’s ratio gives a material several other beneficial effects such as an increased shear stiffness, an increased plane strain fracture toughness and an increased indentation resistance. These properties make auxetics superior to conventional materials for many practical applications [1, 2]. In recent years several auxetics have been fabricated by modifying the microstructure of existing materials, including foams [2] and microporous polymers [3]. A number of molecular auxetics have also been proposed [4–9] one example being α-cristobalite [7]. The auxetic behavior in these materials can be explained in terms of their geometry and deformation mechanism. Thus, the hunt for new auxetic materials is frequently approached through searching for geometric features which may give such behavior [9, 10]. In this letter we present a new mechanism to achieve a negative Poisson’s ratio. This is based on an arrangement involving rigid squares connected together at their vertices by hinges as illustrated in Fig. 1. This may be viewed as a two dimensional arrangement of squares or as a projection of a particular plane of a three dimensional structure. This latter type of geometry is commonly found in inorganic crystalline materials [8, 9, 11]. Referring to Fig. 1, for squares of side length “l” at an angle θ to each other, the dimensions of the unit cell in the Oxi directions are given by:

Patterned crystallisation on self-assembled monolayers with integrated regions of disorder †

This paper describes the engineering of patterned calcite films using templating by self-assembled monolayers (SAMs) supported on micropatterned mixed metal substrates. The substrates were prepared by deposition of one metal (Au, Ag) onto the surface of another metal (Au, Ag) through a stencil or photoresist masks. The micropatterning arises from the generation of disordered regions in SAMs at the interfaces between the two metals, where structurally different SAMs meet. The mechanism of diffusion-limited nucleation on these substrates that governs the formation of different patterns of calcite crystals, crystalline outlines of the underlying patterns, densely crystallised islands and patterned oriented films, is discussed. The ability to control patterned crystallisation with sub-50 nm resolution can find applications in the fabrication of crystalline inorganic materials with complex form.

Vapour Phase Growth of Layered MoO3: A New Kinetic Approach for Volatile Metal Oxides

AbstractA simple yet versatile growth kinetic method (and device) has been developed in conjunction with present vapour phase preparation of layered MoO3 (orthorhombic). Using purified air at atmospheric pressure a sufficient amount of oxygen is warranted to ensure stoichiometry of grown metal oxide. The empirical vapour condensation rate of MoO3 is RE = 1.20×10-3ΔP2.07 over 642 to 660°C, where ΔP is the partial pressure difference of MoO3 between the source and condensed crystals. Based on observed crystal morphology and XRD result, a more precise MoO3 condensation kinetic model has been developed to explain the layer-by-layer growth of the layered structure. The driving force of the condensation growth is investigated with respect to the experimental set-up. On the basis of this work, it is suggested that the new kinetic approach is suitable for other volatile metal oxides or inorganic crystalline materials when an appropriate preparative atmosphere is selected.

B K-edge XANES of crystalline and amorphous inorganic materials

B K-edge x-ray absorption near-edge structure (XANES) spectra of β-B 105, B 4C, h-BN, B 2O 3 and BPO 4, as well as optic fiber glasses in the K 2OSiO 2B 2O 3 system, are reported using a Grasshopper beamline. The chemical shift of the B K-edge is correlated with the oxidation state of B, electronegativity of ligand and coordination geometry of B. The coordination of B in K 2OSiO 2B 2O 3 glasses is also investigated.

Formation and Excretion of Calcareous Bodies by the Metacestode (Tetrathyridium) of Mesocestoides vogae

The function of calcareous bodies, commonly found in the parenchyma of cestodes and trematodes, is relatively poorly understood. The present histochemical ultrastructural study of the proliferative tetrathyridia of Mesocestoides vogae revealed that calcareous corpuscles begin to form as organic (lipid-protein) masses that coalesce in parenchymal (calcareogenic) cells. Concentric accretion of organic and inorganic crystalline material then leads to the formation of typical refractile calcareous bodies. The precise composition of such bodies, determined by x-ray diffraction, revealed that their major inorganic constituent is indeed calcium, with significant amounts of phosphorus, silicon, and zinc as well. Emission of calcareous bodies through the tegument was observed by scanning electron microscopy, explaining their accumulation in the intracapsular spaces around worms embedded in liver tissue of the host. Following their emission, the crystalline substance of corpuscles dissolves, leaving only nonrefractile, membrane-bound cytoplasmic debris. These observations do not preclude the possibility that calcareous bodies may play some role as buffers or reservoirs of inorganic ions. However, it is difficult to accept such a function for unencapsulated worms in the coelom or intestinal lumen; we suggest that excretion is a more likely role in such sites.

Intrinsic mechanical properties and strengthening methods in inorganic crystalline materials

Intrinsic mechanical properties and strengthening methods in inorganic crystalline materials

Optical Properties of Materials for Optical Amplifiers at 1.3 μM

ABSTRACTWe describe the preparation and near Infra-Red fluorescence characteristics of a series of transition metal (V2+, Ni2+, Cr4+) doped crystalline inorganic materials. Within isostructural series, the effect of changes in the host lattice on the transition metal fluorescence has been investigated. This allows selection and fluorescence tuning of transition metal ion/crystalline host combinations of possible use for optical amplification in the 1.31 μm telecommunication window

無機結晶材料の合成と応用

無機結晶材料の合成と応用