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Selective laser melting (SLM) of heat-resistant nickel alloy VZh159 is used to show that at constant energy density the key factor determining the texture and the internal stresses is the hatching distance. At multiple increase in the exposure rate and decrease in the hatching distance, the micropore proportion increases exponentially due to enhancement of the dissipation of the laser radiation caused by reflection in the track overlapping zone. [ABSTRACT FROM AUTHOR]

Analysis of published data on the effect of the exposure algorithms, energy, and scanning speed on the geometric characteristics of the molten pool and its fine structure, on the texture and grain structure of metallic materials synthesized by selective laser melting (SLM) is presented. A regression model describing the correlation between the required laser energy density and the powder composition characteristic temperatures during SLM of heat-resistant nickel- and cobalt-based alloys is obtained. [ABSTRACT FROM AUTHOR]

Experimental results of microstructural studies of refractory nickel alloys obtained by selective laser melting under different crystallization conditions are systematized. The dendritic (cellular) structure and the distribution of the alloying elements in the volume of dendrite arms are studied by scanning and transmission electron microscopy. The detected microsegregation matches a normal crystallization law and is caused by concentration supercooling. It is shown that the main factors responsible for formation of the fine structure of a track are the orientation growth (epitaxy) and the competitive growth of crystallites. The orientation of the crystallites is transferred not only by the first-order arms but also by the second-order arms, and a specific direction is implemented upon coincidence of the crystallographic orientation of the crystallite with the radial direction of the heat removal. The increasing complexity and the fragmentation of the fine structure are associated with the mechanism of stochastic binarization of the crystallographic orientation implemented upon partial remelting and opening of fragments of cells in the current and preceding layers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag particles (40–170 nm) supported on α-Al 2 O 3 are composed of multiple crystallites. • Increasing Ag particle size increases the apparent TOF. • EO selectivity nearly constant with Ag particle size (at zero residence time). • Raman bands at 815 and 880 (Ag > 100 nm) cm−1 identified as active oxygen species. • 880 cm−1 band most likely responsible for higher apparent TOF in large Ag particles. In situ Raman spectroscopy and parallel fixed bed reactor studies were conducted under ethylene epoxidation conditions with O 2 at 1 atm and 200 ℃ on unpromoted Ag/α-Al 2 O 3 catalysts with different Ag particle sizes. It was found that for Ag particles of 20–50 nm, the weight normalized conversion rate decreased rapidly with increasing Ag particle size but remained almost constant above 50 nm. On the other hand, the apparent TOF increased with increasing Ag particle sizes in the 20–170 nm studied range, while ethylene oxide selectivity at zero residence time was nearly constant (55 ± 4%). Raman bands at 815 (all Ag sizes) and 880 (Ag sizes > 100 nm) cm−1 were identified and assigned to active molecular oxygen species. The 880 cm−1 species was assigned to a molecular oxygen complex structure stabilized by subsurface oxygen. The presence of the 880 cm−1 oxygen species likely explain the higher apparent TOF in larger Ag particles (>100 nm). [ABSTRACT FROM AUTHOR]

Molded seal devices made of crystalline polymers are widely used in high-pressure hydrogen equipment. A method for evaluating high-pressure hydrogen permeability was recently reported; however, the evaluation cost is extremely high. To select suitable crystalline polymers for molded hydrogen seals or barrier devices, a high-pressure hydrogen permeability prediction method using the polymer structure and its conventional properties is required. In this study, we measured the pressure dependency of the hydrogen permeability of low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polyamide 11 (PA11). We constructed the permeation model for crystalline polymers in terms of the tortuosity induced by their higher-order structures and free volume change in the amorphous region evaluated using PVT method for measuring the relationship between pressure (p), specific volume (v) and temperature (T) in the molten-solid state of a polymer. The results of the pressure dependency of hydrogen permeability were reproduced by the developed permeation model. [Display omitted] • H 2 permeability of LDPE, HDPE, PA11 are measured under high pressure for two methods. • New permeation model for crystalline polymers is developed in terms of the tortuosity. • The results of pressure dependency of hydrogen permeability are reproduced by developed model. [ABSTRACT FROM AUTHOR]

This research aimed to synthesize the new PHF/n-Eu2O3 nanocomposite, characterize its crystalline structures and morphologies, and correlates them with their optical properties. From the XRD patterns of pure PHF, n-Eu2O3, and PHF/n-Eu2O3 samples, adjusted by the Le Bail method, the unit cells and average apparent size of crystallites (43.86, 61.55, 85.59, and 58.05 Å) were obtained. The SAXS measurements showed that the samples of pure PHF and PHF/n-Eu2O3 are polydisperse. The maximum distance of the pair distribution function of pure PHF indicated a particle size of 67.21 nm, and for PHF/n-Eu2O3 it revealed a large nanoparticle formed by two components with diameters of 96.42 and 119.05 nm. Scanning electron microscopy (SEM) and SAXS revealed globular morphologies of nanoparticles of pure PHF, n-Eu2O3, and PHF/n-Eu2O3. The UV-Vis absorption and photoluminescence spectra showed a clear correlation with the ordering of the polymer chains, crystallinity, presence of the β-phase, and morphology of mixed nanoparticles in the nanocomposite. [ABSTRACT FROM AUTHOR]

The paper investigates the diffusion of Na+ and Cl− in a pore liquid between illite microparticles using the quantum-chemical modeling in Materials Studio. The potential distribution induced by the surface charge of the clay mineral layer, disturbs the uniform distribution of cations and anions observed in the bulk solution. As a result, a layer of immobile cations appears near the microparticle surface. As the distance from the surface grows, the anion concentration grows also, while the potential decreases down to zero. In the appeared double-electric layer, the cation diffusion conditions differ. The particle migration rate in the outer surface of the illite microparticle decreases sequentially for water, anion, cation. [ABSTRACT FROM AUTHOR]

Impact of the nanosized iron powder on the process of thermal degradation of coal tar distillate was determined by the thermogravimetric analysis. Coal tar distillate was obtained by simple distillation up to 350°C of primary coal tar from the Shubarkol deposit. Iron powder was obtained by electrochemical reduction of iron from sulfate electrolytes at simultaneous impact of high-voltage electric discharge on cathodic zone. Scanning electron microscopy showed that iron powder consists of nanosized particles (30-124 nm) forming aggregates. X-ray diffraction analysis revealed the presence of α-Fe and FeO(OH) phases. The average crystallite size determination was made using Scherrer equation and amounted to 31.7 nm. Obtained iron powder was added to the coal tar distillate in amount of 1% of distillate weight and this mixture was subjected to thermal degradation at heating rate 5°C/min in an inert atmosphere. Processing of the data obtained was carried out using the model-fitting Coats-Redfern method. The values of activation energy were calculated from the linear approximation constructed as a result of processing thermoanalytical data. It was found that the addition of iron powder in amount of 1% to the coal tar distillate reduces the activation energy from 153.98 kJ/mol to 84.48 kJ/mol. [ABSTRACT FROM AUTHOR]

The entire world is facing an alarming situation of energy demands and environmental pollution. Single-layer fuel cells are attractive in the era of renewable energy. Developing the materials for single-layer fuel cells (SLFC) is challenging to overcome the low electrical conductivity and polarization losses. In the present research work, novel nanocomposites materials Li 0.1 Ni 0.6 Zn 0.3 O 3-δ (LNZ) have been synthesized by solid-state techniques and Sm 0.2 Ce 0.8 O 2-δ (SDC) via co-precipitation route. Additionally, the effect of 20 wt% of single (Na), binary (Li: Na), and ternary (Li:Na:K) alkali carbonates on the performance of SDC composite material have been analyzed. All novel nanocomposites LNZ + SDC, LNZ + N-SDC, LNZ + LN-SDC, and LNZ + LNK-SDC were milled with 60:40 ratios respectively. Composite material based on 60 wt% LNZ and 40 wt% LN-SDC showed maximum mixed electronic and ionic conductivity of 2.29 Scm−1 at 600 °C with power density of 435mWcm−2. The structural and morphological proprieties of prepared nanocomposite materials were studied using X-Ray diffraction and Scanning electron microscopy respectively. The average crystallite size of 34 nm was observed with LNZ + LN-SDC composite material. The conductivity measurements were done using four-probe techniques and results showed the immense potential of prepared materials for SLFC application. • Alkali carbonated has been developed for one component electrolyte-free fuel cell. • Crystallite size was found to be <100 nm. • The mix conductivity was achieved 2.29 Scm−1 for LNZ + LN-SDC. • The maximum power density was obtained 435 mWcm−2 for LNZ + LN-SDC. [ABSTRACT FROM AUTHOR]

This study aims at designing microwave absorbing composites for controlling electromagnetic (EM) pollution by absorption of EM waves inside the composite material. For this purpose, a light weight and flexible microwave absorber composite was fabricated using reduced graphene oxide (RGO) and W-type barium hexaferrite (BaW) in polyvinylidene fluoride (PVDF) matrix. W-type hexaferrite nanoparticles (BaW) were fabricated by sol–gel auto-combustion method. The fabricated nanoparticles were mixed in PVDF by mechanical grinding. Subsequently, the composites were designed by ultrasonic mixing BaW/PVDF with RGO. The prepared samples were characterized through different techniques for their structural, morphological, and EM properties, as discussed in detail. The X-ray diffractometer results showed the existence of single-phase hexaferrite structure with an average particle size of 48.9 nm. The scanning electron microscope results show that BaW/PVDF is completely embedded in RGO. Dielectric results showed that addition of RGO in BaW/PVDF increases polarization effect, which increases dielectric constant of material. Moreover, RGO decreases the saturation magnetization of composites, which increases the anisotropy constant and hence increases the magnetic loss of material. The composite C3 having RGO to ferrite ratio 15:100 exhibits the maximum reflection loss of −11 dB with broad bandwidth <−10 dB for complete X-band (8.2–12.4 GHz). [ABSTRACT FROM AUTHOR]

Zn2+and Mg2+ions doped Titanium dioxide had been synthesized using a hydrothermal method at 120°C with an annealing temperature at 450°C, including individual Zn2+and Mg2+ ions. In addition, impact of these doping metal ions on the crystallization and phase transition of the Titanium dioxide nanoparticles were discussed by X-Ray Diffraction spectroscopy, Scanning Electron Microscopy, Fourier Transform Infra-Red spectroscopy, UV-Vis spectroscopy and Photo-Luminescence spectroscopy and also by photocatalytic measurements. The presence of anatase type structure in Titanium dioxide nanopowders with high crystallinity and high phase stability in spite of annealing at 450°C significantly specified that the dopants might prevent densification and crystallite growth in Titanium dioxide nanophase by on condition with different boundaries. Furthermore, with a suitable amount of Zn and Mg dopants, anatase grain size of Titanium dioxide powders was reduced. The band gap energy values of Zn2+ and Mg2+ ions doped nano-Titanium dioxide were lower than the pure nano-Titanium dioxide and they exhibited a red shift in the visible region. [ABSTRACT FROM AUTHOR]

Сrystallites in real polycrystals are separated from each other by intergranular space, which affects the effective conductivity of polycrystals. This effect increases with decreasing crystal size. A method for predicting the effective conductivity of polycrystalline media, taking the intergranular space into consideration is developed. The method is constructed using the polycrystal model in which crystallites are considered to be inhomogeneous, consisting of a uniform crystalline anisotropic core and a uniform isotropic shell. In this model, the role of the intergranular gaps is played by crystallite shells. The effective polycrystal conductivity is calculated using the generalized effective-field approximation; the effective medium conductivity is taken as the reference parameter of the medium; i.e., the self-consistent solution method is used. Based on the developed method, a formula for the effective conductivity of polycrystals depending on the conductivity tensor of the crystalline core, shell conductivity, and the core volume fraction in crystallites is derived for the case of spherical crystallites with spherical shells. This formula is applied to particular cases of a polycrystalline medium, i.e., a polycrystal with similar crystallites with isotropic core; in this case, the expression for the effective conductivity is identical to the classical Maxwell–Garnett formula; polycrystals with similar crystallites with anisotropic cores at identical orientations of their crystallographic axes; polycrystals with similar crystallites with anisotropic cores at the uniform distribution of orientations of their crystallographic axes in space; and polycrystals with conductive crystallite cores and absolutely nonconductive shells. In the latter case, the effective polycrystal conductivity vanishes, which is completely consistent with the physical meaning. [ABSTRACT FROM AUTHOR]

The aim of this research was to analyze the crystallites of poly(9,9'-dihexylfluorene) (PHF). The pristine polymer was synthesized through the Suzuki cross-coupling polycondensation and the reprecipitation method. Through XRD measurements it was possible to determine the semicrystalline diffraction pattern of the polymer which after the structural adjustment by Le Bail method showed orthorhombic unit cells and crystallites with average sizes of 43.86 Å. Scanning electron microscopy (SEM), revealed spherical nanoparticles morphology with average diameters equal to 69.20 nm. The possible relationship between the fluorescent properties and the parallel alignment of the chains in the crystallites was determined through the absorption spectra in UV-Vis and photoluminescence. [ABSTRACT FROM AUTHOR]

During the self-catalyzed GaAs nanowire growth formation of parasitic GaAs crystallites is observed. The reasons for crystallite formation are explained on the base of Monte Carlo simulation results. During simultaneous deposition of gallium and arsenic on the GaAs(111)B substrate coated by a silicon oxide film, liquid gallium droplets nucleate on the oxide surface. After nucleation, droplets enlarge in size with time and etch the oxide layer. Formation of GaAs crystal structures becomes possible only after the Ga droplet contacts underlying crystal substrate. It is shown that excessively high arsenic and gallium deposition rates lead to the crystallite formation at the initial growth stage. The GaAs crystallites collect part of the deposited gallium and arsenic decreasing their surface concentration, thereby, adjusting the growth conditions for the nanowire growth. Therefore, during the self-catalyzed GaAs nanowire growth the self-regulation of growth conditions takes place. [ABSTRACT FROM AUTHOR]

Noble metals (Ru, Os, Rh, Ir, Pd, Pt, Ag, and Au) are known for their extraordinary oxidant-resistant behavior, good electrical and thermal conductivity, high work function, and brilliant luster. All occur in close-packed crystal structures: Ru and Os in hexagonal close-packed (hcp) and the rest in face-centered cubic (fcc) structures, both possessing high-symmetry structures and, therefore, a high degree of stabilization. Numerous studies in the literature have attempted to stabilize these metals away from their conventional crystal structures with the aim of realizing new properties. While obtaining conventional fcc metals in hcp structure or vice versa has been the subject of most studies, there are also examples of fcc metals crystallizing in lower-symmetry structures such as monoclinic. The nonnative crystal structures are generally realized during the crystallite growth itself, with a few exceptions in which a posttreatment was required for lattice transformation. In most cases, the new crystal structures pertain to the nanometer-length scale in the form of nanoparticles, nanoplates, nanoribbons, and nanowires, but there are good examples from microcrystallites as well. In this article, we review this active area of research, focusing on ambient stable crystal systems with some account of their interesting properties as reported in recent literature. [ABSTRACT FROM AUTHOR]

The stable EPR signal produced by ionizing radiation in crystalline D-mannose (C6H12O6) and separated from cranberries (Vaccinium oxycoccus) was studied. The isothermal heating of irradiated sample at 95°C for 10 minutes (melting point of D-mannose is 132°C) resulted in the modification and simplification of the EPR signal involved. The isotropic quartet has been recognized in the EPR signal of heat-treated sample. Molecular structure of the isotropic quartet identified in the complex EPR signal of D-mannose crystallite is proposed. [ABSTRACT FROM AUTHOR]

Abstract Polyvinyl alcohol (PVA)-blended NiLa x Fe 2- x O 4 (x = 0.01, 0.03, 0.05, 0.07 and 0.09) nano-ferrites were investigated through characterization studies such as powder X-ray diffraction (XRD) pattern, vibrating sample magnetometer graph, field emission scanning electron microscope (FESEM) images, and electrochemical impedance spectra. XRD pattern showed the presence of spinel cubic structure. A spherical-like morphology of PVA-blended nano-ferrites was identified from FESEM images and it was confirmed that the particle size of PVA-blended NiLa x Fe 2- x O 4 nano-ferrites was approximately 35 nm. An increase in dielectric constant and a decrease in loss tangent as a function of La3+ ions were noted in prepared nano-ferrites. Impedance analysis of PVA-blended NiLa x Fe 2- x O 4 nano-ferrites indicated resistive behavior. PVA-blended NiLa x Fe 2- x O 4 nano-ferrites showed a soft ferromagnetic nature. Further, saturation magnetization of PVA-blended NiLa x Fe 2- x O 4 nano-ferrites decreased while increases the content of La3+ ions. [ABSTRACT FROM AUTHOR]

Zinc Oxide Nanoparticles (ZnO-NPs) were synthesized by chemical precipitation method at low temperature using Zinc nitrate hexa hydrate [Zn (NO 3 ) 2 ·6H 2 O] and sodium hydroxide (NaOH) as precursors followed by annealing at different temperatures ranging from 200 °C to 600 °Cfor two hours. The structural and optical properties of resulting ZnO products were investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), Ultra Violet-Visible ((UV–vis)) Spectroscopy and Photo Luminescence(PL) Spectroscopy respectively. The XRD results reveal that the prepared ZnO-NPs exhibit hexagonal wurtzite structure and the increasing annealing temperatures lead to an increase in the average crystallite size as well as improvement in the crystallinity. SEM images reveal the formation of nearly spherical ZnO nanoparticles with slight agglomeration. The FTIR spectra of all the samples exhibits peak, which corresponds to Zn O stretching band. The UV–Vis absorption spectra show a slight red shift along with decrease in optical band gap from 3.84 eV to 3.56 eV with increase in annealing temperature. The room temperature PL spectra with excitation wavelength 320nm show increase in UV emission intensity with respect to annealing temperature. [ABSTRACT FROM AUTHOR]

Crystallite formation in membranes cast from sulfonated poly(etheretherketone) (SPEEK) dispersions in dimethylacetamide has been investigated by differential scanning calorimetry. The crystallites melt at 220 °C and the melting enthalpy (ΔH m ) is strongly influenced by environmental conditions of solvent evaporation. When solvent is evaporated in air, ΔH m decreases with increasing the evaporation temperature so that no crystallites are formed above 45 °C. The study of crystallite formation at 30 °C, under controlled relative humidity (RH) and solvent evaporation rate, has shown that ΔH m decreases i) with decreasing RH from 75% to 5%, at constant evaporation rate, and ii) with increasing evaporation rate, especially at low RH. The exchange of protons with sodium ions results in an increase of the crystallite melting temperature thus indicating the presence of sulfonic groups in the crystallites. In comparison with crystallite-free SPEEK membranes, the presence of crystallites turns out in enhanced membrane mechanical properties, reduced hydration in liquid water above 75 °C, strongly anisotropic swelling (occurring mainly in the through-plane direction) and better performance in H 2 /air fuel cell at 70 °C. [ABSTRACT FROM AUTHOR]

Ba(0.85-x)NdxCa0.15Zr0.1Ti0.9O3(x= 0, 0.005, 0.010, 0.015, 0.020, 0.025) ceramic compositions were synthesized by solid state reaction method. Effects of Nd3+on the microstructure, dielectric, and piezoelectric properties of the ceramics were studied. X-ray diffraction study reveals that Nd3+ions diffuse into Ba(0.85-x)NdxCa0.15Zr0.1Ti0.9O3lattice to form a solid solution of single perovskite structure having tetragonal symmetry. It was found that cell volume, crystallite size, tetragonality, d33and Prchange with increasing Nd3+content.d33was optimized at 270pC/N forx= 0.015. The study reveals that optimum doping of Nd3+in Ba(0.85-x)NdxCa0.15Zr0.1Ti0.9O3can enhance its dielectric and piezoelectric properties. [ABSTRACT FROM AUTHOR]

Iron nanopowders ranging in particle size from 20 to 100 nm have been synthesized by reducing a 1-mm-thick iron(III) hydroxide layer in flowing hydrogen at 400°C and then passivated for 6-60 min in flowing argon containing 3% air. Our results demonstrate that the passivated iron nanopowders do not oxidize in air for six months. The iron nanoparticles have been characterized by X-ray diffraction (crystallite size evaluation), Auger electron spectroscopy, and polymolecular adsorption. The passivated iron nanoparticles have been shown to consist of a metallic core and oxide shell 2-4 nm in thickness. [ABSTRACT FROM AUTHOR]

Tin monosulfide (SnS) films were grown by sulfurization of sputtered Sn thin films. The effect of S vapor pressure ( PS), which varied from 10 to 105 Pa, was analyzed through depth profiling of SnS films. S atoms were diffused into the surface regions of the SnS layer to approximately 100 nm at PS = 10 Pa. The activation energy for S diffusion in the Sn thin films was 1.4eV. At PS = 103 Pa, on the other hand, S atoms were diffused into the SnS layer to a depth of approximately 700 nm. Accordingly, the activation energy was 1.1 eV. The experimentally obtained crystallite size was found to increase from 12 to 35 nm with the increase of S vapor pressure. Furthermore, by varying the sulfurization temperature range, a similar tendency was likewise observed. Under the photovoltaic properties with a structure of Al/ZnO:Al/ZnO/CdS/SnS/Mo/SLG, a current density of 6.2 mA cm−2 was obtained when the SnS crystallite size was 35 nm. [ABSTRACT FROM AUTHOR]

A hybrid catalyst was prepared using cellulose nanofibrils and magnetite to degrade organic compounds. Cellulose nanofibrils were isolated by mechanical defibrillation producing a suspension used as a matrix for magnetite particles. The solution of nanofibrils and magnetite was dried and milled resulting in a catalyst with a 1:1 ratio of cellulose and magnetite that was chemically and physically characterized using light, scanning electron and transmission electron microscopies, specific surface area analysis, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, catalytic potential and degradation kinetics. Results showed good dispersion of the active phase, magnetite, in the mat of cellulosic nanofibrils. Leaching and re-use tests showed that catalytic activity was not lost over several cycles. The hybrid material produced was tested for degradation of methylene blue dye in Fenton-like reactions resulting in a potential catalyst for use in degradation of organic compounds. [ABSTRACT FROM AUTHOR]

SrFe 0.5 Ti 0.5 O 3−δ perovskite-structured ceramic was produced using wet processing method namely glycine-nitrate combustion technique. The quality of powders produced through this wet processing method was strongly related to processing parameters and heat treatment. This study investigated the effect of calcination temperature and mixing time of nitrate solution on the formation of SrFe 0.5 Ti 0.5 O 3−δ . Results revealed that calcination temperature and mixing time significantly affected the purity and average crystallite size of SrFe 0.5 Ti 0.5 O 3−δ . The crystallite grew to 31.48 nm when the calcination temperature was increased, whereas small crystallites (∼30 nm) were produced when the mixing time was prolonged. In terms of the purity of powders, XRD analysis indicated that secondary phases (Sr 3 Fe 2 O 7 and TiO 2 ) were retained when the calcination temperature was further increased to 1300 °C. As the mixing time was prolonged, secondary phases were removed. After 15 h of mixing, the lowest intensity of secondary peak was observed. The effects of mixing time on the production of pure and fine crystallites of SrFe 0.5 Ti 0.5 O 3−δ powders were more significant than those of calcination temperature. Thus, mixing time should be prolonged until the optimum duration is reached to produce pure SrFe 0.5 Ti 0.5 O 3−δ perovskite-structured ceramic powders. [ABSTRACT FROM AUTHOR]

The paper examines physical properties of foam glass material modified with 0.3 mass% nano-sized zirconium dioxide. It presents experimental data on the foam glass structure on micro- and meso-levels. The authors make a conclusion about influence and mutual subordination of structural levels in the glass materials. The presence of nanocrystallites (25 nm) located in the amorphous matrix in an ordered fashion and the pore packing that is correct from the symmetry standpoint provide for the enhanced strength of the porous structure. Findings show that the introduction of nano-sized zirconium dioxide leads to the emergence of a hierarchical and mutually subordinate system. The paper concludes that small additions of zirconium oxide have a positive effect on physical and mechanical properties of foam glass material. [ABSTRACT FROM AUTHOR]

For Alan Mackay, on his 90th birthday, we recast his notion of crystalloids and crystallites as finite nano-sized sphere packings and discuss current mathematical/computational research on their geometric structures. We suggest that icosahedral clusters are (metaphoric) stem cells for condensed matter. [ABSTRACT FROM AUTHOR]

Spin-crossover (SCO) triazole-based coordination polymers can be synthesized by micelle techniques, which almost always lead to rod-shaped nanoparticles. In order to notably reach new morphologies, we explore here the potentiality of the spray-drying (SD) method to get SCO materials. Three SCO coordination polymers and a mononuclear complex are investigated. In all cases, the SD method obtains particles definitely showing SCO. The features of the latter are yet always different from those of the referenced materials, in the sense that SCO is more gradual and incomplete, in adequacy with the poor crystallinity of the powders obtained by SD. In the case of coordination polymers, the particles are preferentially spherical. Indications of possible polymorphism and/or new materials induced by the use of the SD method are evidenced. In the case of the mononuclear complex, the SD method has allowed reproducing, in a quick and easy way, the well-known bulk compound. This exploratory work demonstrates the relevance of the concept and opens the way to a systematic scrutiny of all the experimental parameters to tune the size, morphology, and properties of the SD-synthesized SCO particles. [ABSTRACT FROM AUTHOR]

Networked rod-like and intersecting flake-like CdS crystallites with three-dimensional structures were synthesized using a thermal evaporation method. Both types of CdS crystallites had a hexagonal crystal for given growth conditions. The rod-like CdS crystallites contained many irregular CdS grains, whereas the flake-like CdS crystallites comprised many granular CdS grains with various sizes. Furthermore, the flake-like CdS crystallites were more defective than the rod-like CdS crystallites because they contained a larger number of grain boundaries and showed greater sulfur deficiency. Additionally, the flake-like CdS crystallites showed higher photocatalytic activity and photoelectrochemical performance. The substantial differences in the microstructure and optical properties between the two types of CdS crystallites explained the superior photoactivated properties of the flake-like CdS crystallites. [ABSTRACT FROM AUTHOR]

The stable and complex EPR signals produced by the action of ionizing radiation on crystalline L-sorbose (C6H12O6) separated from rowan berries (Sorbus aucuparia) were studied. Isothermal heating of the samples at the temperature close to the melting point of L-sorbose (140°C) results in the modification and simplification of the EPR signal involved. In the EPR signal of heated L-sorbose, the isotropic quartet was distinguished. In the differential spectrum obtained by subtraction of normalized spectra of unheated and heated L-sorbose, the isotropic doublet was identified in addition. The DFT fitting offers the probable assignment of the EPR signals to specific radical structures. [ABSTRACT FROM AUTHOR]

Nanoparticles of basic composition Sn 0.94 Zn 0.05 Co 0.01 O 2 , Sn 0.92 Zn 0.05 Co 0.03 O 2 and Sn 0.90 Zn 0.05 Co 0.05 O 2 were synthesized by chemical precipitation method. The incorporation of Co and Zn in SnO 2 lattice introduced significant changes in the physical properties of all the three nanocrystals. The average particle size estimated from TEM data decreased from 15.71 to 6.41 nm with enhancement in concentration of oxygen vacancies as Co content is increased from 1 to 5 wt%. Increasing Co content enhanced the Sn:O atomic ratio as a result concentration of oxygen vacancies increased. The dielectric study revealed strong doping dependence. The dielectric parameters (ε′, tanδ and σ ac ) increased with increasing Co content and attained maximum values for 5% (Zn, Co) co-doped SnO 2 nanoparticles. The dielectric loss (ε′′) exhibited dispersion behavior and the Debye’s relaxation peaks observed in dielectric loss factor (tanδ), whose intensities increased with increasing Co content. The variation of dielectric properties and ac conductivity revealed that the dispersion is due to Maxwell-Wagner interfacial polarization and hopping of charge carriers between Sn +2 /Sn +3 and Co +2 /Co +3 . The large dielectric constant of all samples made them interesting materials for device application. Magnetization measurements (M (H) loops) revealed enhancement in saturation magnetization with doping which is due to the formation of large amount of induced defects and oxygen vacancies in the samples. The present study clearly reveals doping dependent properties and the oxygen vacancies induced ferromagnetism in Zn, Co co-doped SnO 2 nanoparticles having applications in ultra-high dielectric materials, high frequency devices and spintronics. [ABSTRACT FROM AUTHOR]

Graphene-based nanostructured systems and van der Waals heterostructures comprise a material class of growing technological and scientific importance. Joining materials with vastly different properties, polymer/graphene heterosystems promise diverse applications in surface and nanotechnology, including photovoltaics or nanotribology. Fundamentally, molecular adsorbates are prototypical systems to study confinement-induced phase transitions exhibiting intricate dynamics, which require a comprehensive understanding of the dynamical and static properties on molecular time and length scales. Here, we investigate the dynamics and the structure of a single polyethylene chain on free-standing graphene by means of molecular dynamics simulations. In equilibrium, the adsorbed polymer is orientationally linked to the graphene as two-dimensional folded-chain crystallite or at elevated temperatures as a floating solid. The associated superstructure can be reversibly melted on a picosecond time scale upon quasi-instantaneous substrate heating, involving ultrafast heterogeneous melting via a transient floating phase. Our findings elucidate time-resolved molecular-scale ordering and disordering phenomena in individual polymers interacting with solids, yielding complementary information to collective friction and viscosity, and linking to recent experimental observables from ultrafast electron diffraction. We anticipate that the approach will help in resolving nonequilibrium phenomena of hybrid polymeric systems over a broad range of time and length scales. [ABSTRACT FROM AUTHOR]

The structural and luminescent properties of Sm 3+ doped NaSrVO 4 phosphors prepared by the combustion method were investigated. The phosphors were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL) and diffuse reflectance spectroscopy (DRS). NaSrVO 4 crystallized into the monoclinic phase with P2 1/ n space group. The Debye Scherrer׳s formula and Williamson–Hall (W–H) plot were used to determine the average crystallite size of the phosphors. Upon near-UV excitation, the phosphor gives the characteristic orange–red emission ascribed to the intra-4 f -shell 4 G 5/2 to 6 H J ( J =5/2, 7/2, 9/2, 11/2) transitions of Sm 3+ . The diffused reflectance spectra of the phosphors were used to calculate the optical band gap ( E g ) of the material, which was estimated to be 3.58 eV. The chromaticity coordinates ( x =0.61, y =0.39) of the phosphors further validated the orange–red emission of the material. This phosphor may be used as near ultraviolet (n-UV) convertible orange–red emitting phosphor in light emitting diodes (LEDs). [ABSTRACT FROM AUTHOR]

Cerium dioxide is widely studied due to its potential interest in several applications, including heterogeneous catalysis. In this field, modifications of the crystallographic orientations and surface reactivity of CeO 2 can lead to activity loss of metal supported catalysts. In situ High Temperature-Environmental Scanning Electron Microscopy observations were then developed to monitor such evolution in CeO 2 spherical particles. Microspheres with 300–800 nm diameter were heat treated for 1–120 min in the 1000–1200 °C range. Subsequent image analysis led to monitor and quantify the crystallite growth during isotherm dwells. Two distinct mechanisms controlling the growth of crystallites in a single microsphere were then evidenced depending on the heating duration, i.e. oriented attachment then diffusion. Precise control of the aggregates inner structure (number of crystallites and density) was also achieved and described as a nanostructure map. These results pave the way to new opportunities in nanoparticle design. [ABSTRACT FROM AUTHOR]

In this study, nanocrystalline hydroxyapatite and biphasic calcium phosphate prepared via wet chemical precipitation technique in an isolated N2 environment that utilizes calcium hydroxide and ammonium dihydrogenphosphate as main precursors, is presented. Formation of predominantly hydroxyapatite with increasing crystallinity from 39.6 to 88.3% with corresponding crystallite sizes of ∼20.6 and ∼46.6 nm were found for the as-grown and the annealed powders, respectively. Partly phase transition of hydroxyapatite to β-TCP phase forming biphasic calcium phosphate was observed in the 900 oC annealed powders. Aggregated structures with nanopores were depicted on the surface of the as-grown sample while interconnected worm-like structures with voids forming nanopores were found for the sample annealed at 900 oC. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Highlights: [•] SiO2 incorporated TiO2 crystallites were used for transmission enhanced photoanodes. [•] Excitation of dye molecules was significantly elevated. [•] An efficiency of 9.98% was recorded on DSSC from 1 wt% SiO2 incorporated TiO2. [Copyright &y& Elsevier]

• Merwinite was prepared by solution combustion synthesis by using glycine, urea and citric acid as fuels. • All 3 fuels produced pure merwinite with different particle size. • Bioactivity of the merwinite prepared by 3 different fuel shows different surface coverage during bioactivity studies. • Citric acid is found to be a better fuel among the 3 fuels. Merwinite undrapes proficient characters like profound mechanical strength, cytocompatibility, cell proliferation and osteointegration. Merwinite was prepared through solution combustion technique by using glycine, urea and citric acid as fuels. Pure phases of merwinite were achieved at 900 °C in which citric acid resulted in 23–28 nm crystals whereas glycine and urea produced particles in the range of 31–34 nm and 40–45 nm respectively when characterized by powder X-ray diffraction. Invitro biomineralization of scaffolds were investigated in simulated body fluid (SBF) for 9 days. The XRD pattern recorded after bioactivity studies demonstrated that merwinite obtained by using citric acid as a fuel shows complete coverage of the surface due to the deposition of hydroxyapatite whereas the merwinite prepared by using glycine and urea as a fuel shows lesser extent of hydroxyapatite deposition. SEM images of hydroxyapatite nucleated on the merwinite prepared using citric acid and urea as a fuel shows smaller particle size when compared to glycine as a fuel. Citric acid emerges out as a better fuel among the three fuels as the product formed is found to have better bioactivity. [ABSTRACT FROM AUTHOR]

The gel-like phase constructed by fatty acid compounds is a kind of fascinating soft matters but its structural characteristics have not been fully understood. This work has investigated the crystalline structures and formation mechanism of gel-like phase containing potassium stearate (KS), stearic acid (SA), and water at 80% neutralization degree. The crystalline fibers are observed in the gel-like samples of KS-SA-water on the polarized optical microscopy. X-ray diffraction measurement demonstrates that there are two isolate types of lamellar crystallites of KS and KS-SA complexes instead of the mixed crystallites in KS-SA-water samples. While KS crystallites have shorter Bragg spacing and tilted angle than the crystallites of KS-SA complexes, it is found that the solvent of water does not penetrate in the interlayer of two kinds of crystallites. The dynamic rheology measurement suggests the strong elasticity of KS-SA-water samples, which indicates the network structure formed by the lamellar crystalline fibers entrapping water. The addition of glycerol does not affect the crystalline structures of KS-SA-water samples, but significantly increase the values of storage modulus and melting enthalpy. This result suggests that the added glycerol can promote the strength of the hydrogen bonding between the solvent and crystalline fibers in the network structure of KS-SA-water samples. These findings provide new insights to the structural properties of gel-like phase of fatty acid compounds, which are importantly helpful for controlling their structure and functions. [Display omitted] • There are two isolate types of lamellar crystallites of KS and KS-SA complexes. • Water and glycerol do not penetrate in the interlayer of lamellar crystallites. • Network structure is formed by the crystalline fibers entrapping the solvent. • Glycerol can promote the hydrogen bonding between the solvent and crystallites. [ABSTRACT FROM AUTHOR]

• The composite film of Chitosan and 2-[(4‑tert-butylphenyl)−5–(4-biphenyl)]−1, 3, 4- oxadiazole (PBD) was prepared by solvent casting technique via gamma irradiation. • The prepared films showed a hypsochromic shift before irradiation and bathochromic shift after irradiation. • The Π-Π stacking of the dopants between the chains were responsible for blue emission • The chemical crosslinking by gamma irradiation enhanced the mechanical properties of CHPBD films. • This eco-friendly biopolymer doped films might find applications in optoelectronics. Herein, versatile biopolymer chitosan films doped with 2-[(4-‑tert-butylphenyl)-5–(4-biphenyl)]-1, 3, 4- oxadiazole (PBD) a known OLED material were prepared by intercalation method. These films witnessed crosslinking which in turn exhibited exciting properties due to gamma irradiation with varied dosages. The radical mediated crosslinking of NH 2 group with t‑butyl group was envisaged by the increased crystallinity of the films. The XPS analysis showed the formation of the bond between dopant and polymer backbone. The changes in binding energies of unirradiated and irradiated CHPBD films for N1s from 399.08 eV (1° amine) to 400.7 eV (2°amine), supported reaction of NH 2 group with t‑butyl group of PBD in crosslinking of dopant and polymer matrix with the formation of C N linkage. In PXRD, peaks centered around 21.24° for pristine chitosan film, but for the unirradiated CHPBD, it was shifted to the lower angle16.09° to form amorphous film. However, for the irradiated CHPBD shifting to the higher angle 22.9°, 23.08°, 27.23° suggesting that dopant had chemically interacted with the polymer matrix. The Young's modulus, tensile strength indicated supportive properties. An interesting change in UV absorption behavior was observed for the unirradiated CHPBD exhibiting λ max at 290 nm with a hypsochromic shift with respected to dopant (λ max ,309 nm). This indicated weak head-to-head alignment of dyes in an unirradiated matrix; whereas irradiation brought about changes through chemical crosslinking in the architecture of films with a redshift to 309 nm. Hyperchromism was also the effect of irradiation on films. The unirradiated films exhibited emission maxima around 369 nm whereas irradiated films showed 412 nm. Hence, a simple method was developed for the preparation of blue emissive biopolymeric materials. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, untreated bovine cortical bones (BCBs) were exposed to a range of heat treatments in order to determine at which temperature the apatite develops an optimum morphology comprising porous nano hydroxyapatite (nanoHAp) crystals. Rectangular specimens (10 mm × 10 mm × 3-5 mm) of BCB were prepared, being excised in normal to longitudinal and transverse directions. Specimens were sintered at up to 900 °C under ambient pressure in order to produce apatites by two steps sintering. The samples were characterized by thermogravimetric analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM) attached to an energy-dispersive X-ray spectroscopy detector. For the first time, morphology of the HAp particles was predicted by XRD, and it was verified by SEM. The results show that an equiaxed polycrystalline HAp particle with uniform porosity was produced at 900 °C. It indicates that a porous nanoHAp achieved by sintering at 900 °C can be an ideal candidate as an in situ scaffold for load-bearing tissue applications. [ABSTRACT FROM AUTHOR]

Platinum (Pt) doped nanofibers were electrospun by using a Pt-TiO2 precursor solution. The Pt-TiO2 precursor solution was prepared by mixing the synthesized metal-organic precursor solution containing Ti and Pt and the TiO2 sol. Amino acid, L-lysine, was used as a bonding medium between Ti and Pt. The required amount of L-lysine was determined to be 12 wt%. The dynamic viscosity and surface tension of Pt-TiO2 solution were 16.6 cP and 21.4 mN/m, respectively. SEM results revealed that the diameters of TiO2 and Pt-TiO2 nanofibers calcined at 500°C were similar regardless of the Pt presence. However, crystallite sizes of TiO2 and Pt-TiO2 nanofibers determined by the Scherrer formula were 16 nm and 8 nm, respectively, suggesting that Pt metals may hinder the growth of the crystallite (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Abstract: The influence of film thickness, type of buffer underlayer, and deposition substrate temperature on the crystal structure, microstructure, and morphology of the films of dicyanovinyl-substituted sexithiophene with four butyl-chains (DCV6T-Bu4) is investigated by means of X-ray diffraction (XRD) and X-ray reflectivity methods. A neat Si wafer or a Si wafer covered by a 15nm buffer underlayer of fullerene C60 or 9,9-Bis[4-(N,N-bis-biphenyl-4-yl-amino)phenyl]-9H-fluorene (BPAPF) is used as a substrate. The crystalline nature and ordered molecular arrangement of the films are recorded down to 6nm film thickness. By using substrates heated up to 90°C during the film deposition, the size of the DCV6T-Bu4 crystallites in direction perpendicular to the film surface increases up to value of the film thickness. With increasing deposition substrate temperature or film thickness, the DCV6T-Bu4 film relaxes, resulting in reducing the interplane distances closer to the bulk values. For the films of the same thickness deposited at the same substrate temperature, the DCV6T-Bu4 film relaxes for growth on Si to BPAPF to C60. Thicker films grown at heated substrates are characterized by smaller density, higher roughness and crystallinity and better molecular ordering. A thin (up to about 6nm-thick) intermediate layer with linear density-gradient is formed at the C60/DCV6T-Bu4 interface for the films with buffer C60 layer. The XRD pattern of the DCV6T-Bu4 powder is indexed using triclinic unit cell parameters. [Copyright &y& Elsevier]

Wright JT, Li Y, Suggs C, Kuehl MA, Kulkarni AB, Gibson CW. The role of amelogenin during enamel-crystallite growth and organization in vivo. Eur J Oral Sci 2011; 119 (Suppl. 1): 65-69. © 2011 Eur J Oral Sci Amelogenin is critical for enamel formation, and human amelogenin gene ( AMELX) mutations cause hypoplastic and/or hypomaturation enamel phenotypes. The Amelx null (AKO) mouse has a severe hypoplastic phenotype. This study evaluated the effect of amelogenin loss on enamel formation and crystallite morphology. Enamel from AKO and wild-type (WT) mice was used. The AKO mice were mated with transgenic mice expressing the most abundant known amelogenin isoform, TgM180-87, to rescue (KOM180-87) the enamel crystallite phenotype. Molar enamel was embedded, sectioned with a diamond microtome, and images were obtained by transmission electron microscopy. The crystallite sizes from multiple sections were measured using I mage J. The mean thicknesses (WT = 26 nm, AKO = 16 nm, and KOM180-87 = 25 nm) and the mean widths (WT = 96 nm, AKO = 59 nm, KOM180-87 = 85 nm) of crystallites were measured. Despite a complete loss of amelogenin in AKO mice, a mineralized enamel layer with well-defined and organized crystallites is formed. In the absence of amelogenin, enamel crystallites were reduced in thickness and width. For the first time we show that introduction of the m180 amelogenin isoform into the AKO mouse through cross-breeding rescues the crystallite phenotype. We conclude that amelogenin is essential for the development of normal crystallite size. [ABSTRACT FROM AUTHOR]

Abstract: The mechanisms of iron precipitation and crystallization in a fluidized-bed reactor were investigated. Within the typical Fenton’s reagent dosage and pH range, ferric ions as a product from ferrous ion oxidation would be supersaturated and would subsequently precipitate out in the form of ferric hydroxide after the initiation of the Fenton reaction. These precipitates would simultaneously crystallize onto solid particles in a fluidized-bed Fenton reactor if the precipitation proceeded toward heterogeneous nucleation. The heterogeneous crystallization rate was controlled by the fluidized material type and the aging/ripening period of the crystallites. Iron crystallization onto the construction sand was faster than onto SiO2, although the iron removal efficiencies at 180 min, which was principally controlled by iron hydroxide solubility, were comparable. To achieve a high iron removal rate, fluidized materials have to be present at the beginning of the Fenton reaction. Organic intermediates that can form ferro-complexes, particularly volatile fatty acids, can significantly increase ferric ion solubility, hence reducing the crystallization performance. Therefore, the fluidized-bed Fenton process will achieve exceptional performance with respect to both organic pollutant removal and iron removal if it is operated with the goal of complete mineralization. Crystallized iron on the fluidized media could slightly retard the successive crystallization rate; thus, it is necessary to continuously replace a portion of the iron-coated bed with fresh media to maintain iron removal performance. The iron-coated construction sand also had a catalytic property, though was less than those of commercial goethite. [Copyright &y& Elsevier]

Objectives: The aim of this study was to evaluate the mineralizing potential of ions released from surface pre-reacted glass-ionomer (S-PRG) fillers on mineral induction by phosphoprotein in vitro.Methods: Phosvitin was used as a model of dentin phosphoprotein in this study. Phosvitin was immobilized on agarose beads with divinyl sulfone. Five aliquots of phosvitin-immobilized agarose beads were incubated in control or experimental mineralizing solution. The experimental mineralizing solutions were made from eluates of resin filled with S-PRG fillers. The beads were incubated at 37°C in a shaking water bath, and aliquots were taken at several time points during the incubation. Then the beads were analyzed for calcium by atomic absorption spectrometry.Results: Phosvitin-immobilized agarose beads induced mineral formation after incubation for 5.3h in the metastable solution without ions eluted from S-PRG fillers. Undiluted eluates significantly reduced mineral induction time. SEM observation and X-ray diffraction revealed larger apatite crystals on the beads incubated with eluates of S-PRG fillers than with the control.Conclusions: S-PRG fillers may play a role in mineral induction. [ABSTRACT FROM AUTHOR]

Abstract: Wear resistant Ti(C,N) coatings were produced by changing the heating rate during the chemical vapor deposition process (CVD). The modification of the CVD process led to the formation of Ti(C,N) coatings with a particulate grain architecture consisting of two different crystallites (star-shaped and lenticular-like morphologies) co-existing in the coating layer. The microstructure formation of the Ti(C,N) layer was investigated by interrupting the CVD process at different temperatures. Depending on the deposition temperature, rounded, star-shaped and/or lenticular-like crystallites formed. The overall C/N ratio of the Ti(C,N) layer was 0.16/0.84, as determined by x-ray diffraction. TEM/EELS investigations of Ti(C,N) crystallites revealed an inhomogeneous distribution of carbon and nitrogen in the grains. Cutting tests showed outstanding wear resistance of the Ti(C,N) layers produced by the modified CVD process. [ABSTRACT FROM AUTHOR]

Abstract: A crystallite-scale model is incorporated into a reactor-scale model to study the effect of Pt dispersion and temperature during the regeneration of a lean NO x trap (LNT) comprising a Pt/BaO catalyst. The current study is based on a recent experimental study [R.D. Clayton, M.P. Harold, V. Balakotaiah, C.Z. Wan, Appl. Catal. B 90 (2009) 662]. The model shows that an increase in the Pt dispersion for a fixed Pt loading increases the interfacial perimeter between Pt and Ba, and has a significant effect on the regeneration kinetics. The transient product distribution displayed by three catalysts having varied Pt dispersions (3.2%, 8% and 50%) is explained by the localized stored NO x gradients in the Ba phase. A rate determining process during the regeneration is found to be the diffusion of stored NO x within the Ba phase towards the Pt/Ba interface. Temperature-dependent NO x diffusivities in the Ba phase are used to predict the breakthrough profiles of H2, N2 and NH3 over a range of catalyst temperatures. Finite gradients in the stored NO x concentration are predicted in the Ba phase, thus showing that the nitrate ions are not sufficiently mobile at lower temperatures for the low dispersion catalysts. The model predicts that the highest amount of NH3 is produced by the low dispersion catalyst (3.2% dispersion) at high temperatures, by the high dispersion catalyst (50% dispersion) at low temperatures, and by the intermediate dispersion catalyst (8% dispersion) at intermediate temperatures, consistent with the experimental data. It is found that the net NH3 generation is favored under conditions when NO x transport to the Pt/Ba interface is the rate determining process. The model considers the consumption of chemisorbed oxygen on Pt by H2, which is used to predict the low effluent N2 concentration for the 50% dispersion catalyst as compared to the 8% dispersion catalyst. Finally, a novel design is proposed to maximize the amount of NH3 in the effluent of a LNT, which can be used as a feed to a selective catalytic reduction (SCR) unit placed downstream of the LNT. [Copyright &y& Elsevier]

Abstract: A novel iron titanate catalyst prepared by conventional co-precipitation method showed excellent activity, N2 selectivity and H2O/SO2 durability in the selective catalytic reduction (SCR) of NO with NH3. The influence of precursors and preparation methods on the catalyst structure and activity was comprehensively investigated. Iron titanate catalyst prepared using titanium sulfate as Ti precursor was favorable for the high activity and selectivity, comparing with that using titanium tetrachloride as precursor and Fe2O3/TiO2 loaded type catalyst. Especially, the best iron titanate catalyst showed good activity in a temperature window of 200–350°C with the NO x conversion above 90% in the absence of H2O, which was 50–150°C lower than those of other known Fe-based catalysts. Iron titanate crystallite with specific Fe–O–Ti structure was found to be the main active phase. The interaction between iron and titanium species in atomic scale led to an enhancement of oxidative ability of Fe3+, which was beneficial to the SCR reaction. [Copyright &y& Elsevier]

Iron-platinum (FePt) nanostructured thin films were deposited on brass substrates using a novel stable single bath electrodeposition system. Complex-forming additive was added to stabilise the Fe2+ ions. The composition of the electrodeposited film was controlled by varying current density, concentration of the electrolytes and concentration of the complex-forming additive in the electrolyte. The as synthesised FePt films were characterised by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and scanning electron microscopy (SEM). energy dispersive X-ray spectroscopy showed that FePt films deposited from solution with Fe2+/Pt4+ molar ratio of 25 : 25 contained higher amount of Fe, in proportion with increasing concentration of complex-forming additive in the electrolyte. However, FePt thin film with higher platinum content was obtained from solution with Fe2+/Pt4+ molar ratio of 200 : 1 and without complex forming additive. X-ray diffraction characterisation showed formation of disordered face centred cubic FePt in the as deposited films while the Fe-rich film exhibited body centred cubic lattice structure. The average crystallite size of deposited films varied from 4·3 to 39 nm. The crystallite sizes estimated from XRD peak broadening were smaller than the those observed by SEM, indicating that the grains were polycrystalline. [ABSTRACT FROM AUTHOR]

Abstract: In-doped ZnO (ZnO:In) nanocrystals with various In-contents have been successfully synthesized by vapor phase condensation of mixed source. Hexagonal phase ZnO:In samples with high In-concentration (∼25at.%) were easily obtained and structural phase transformation was observed at ZnO:In nanocrystal with an In-concentration of ∼35at.%. Near band edge (NBE) emission shifted to lower energy side and increase of emission intensity were observed from photoluminescence (PL) measurement, which was explained in terms of the increase of extrinsic carrier concentration. Diffuse-reflectance spectra (DRS) show free-carrier absorption band at 0.6–2.0eV, which corresponds with the PL results. [Copyright &y& Elsevier]

The crystal growth and morphological changes of C. I. Disperse Blue 79 in supercritical CO2 were investigated using scanning electron microscopy, X-ray diffraction and differential scanning calorimetry. Crystals of the undissolved dye grew in the supercritical fluid and the melting point and crystallinity of this undissolved dye increased with increasing temperature and pressure. [Copyright &y& Elsevier]