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Zinc tungstate crystal scintillator is an interesting detector material for double beta decay, dark matter, and rare alpha decay experiments. The luminescence under X-ray excitation in the temperature region from 85 K to 420 K was studied with five samples of ZnWO 4 crystals developed by different methods: with a stoichiometric composition, and with excess of Zn or W. It is found that doping a ZnWO 4 crystal with 0.2–0.3% Zn and W does not affect the luminescence properties of the material. A theoretical dependence of the sample luminescence intensity on the competing nonradiative recombination centers and traps is obtained. The main center of the recombination luminescence in a ZnWO 4 crystal with a spectral maximum at 2.5 eV is the tungsten complex with a structural defect located next to it. • The studies of XRL, the dose and temperature dependencies, optical absorption, phosphorescence and TSL of five samples have been carried out. • The main center of recombination luminescence with a spectral maximum at 2.5 eV in ZnWO₄ crystals is a tungsten complex. • The luminescence excitation of the band at 2.5 eV, which starts at 3.6 eV, is the intra-center excitation of the luminescence center. • The double crystallization leads to a decrease in the intensity of X-ray luminescence, phosphorescence, and TSL. • That indicates an increase in the uncontrolled concentration of competing centers of nonradiative recombination. [ABSTRACT FROM AUTHOR]

A miniemulsion-basedapproach to produce crystalline ZnO nanoparticleswith narrowly distributed sizes and well-defined faces and shapesis presented. The synthesis reaction in the aqueous droplets of thewater-in-oil miniemulsion is induced by mass transfer of the basetriethylamine (TEA) across the liquid/liquid interface. In a preliminarystudy, the dosage of TEA was determined to ensure the required pHrange in the aqueous phase. Miniemulsions with a mean droplet sizeof about 200 nm were produced with a rotor–stator device. Theaqueous zinc salt concentration was varied as the parameter in theexperimental study. At low zinc salt concentrations, platelike nanoparticleswere obtained. An increase in the zinc ion concentration resultedin a decrease in the mean particle size. The shape of the ZnO crystalschanged from platelike to rodlike. On the basis of the resulting particlesize, it can be deduced that interdroplet exchange is an essentialpart of the presented miniemulsion-based process. [ABSTRACT FROM AUTHOR]

This paper investigates the process of crystallisation of the copper and zinc dendritic deposits under galvanostatic conditions on the rod electrode. The effect of the value of current and metal ion concentration in solutions on the growth dynamics of loose deposits is studied. It is shown that the current efficiency of the metal increases, and the growth rate decreases during the elongation of dendritic particles, and an increase in the surface area on which the electrocrystallisation takes place. Empirical equations for the quantitative description of changes in time of the lengths of the dendrites and the current efficiency of copper and zinc are proposed, which well approximate the experimental data obtained under various conditions of electrolysis. A phenomenological model is worked out that helps to calculate the variation of structural parameters in time (the number and the radius of tips of the dendrite branches) of the loose deposit growth and to determine the moment of transition from a loose deposit to a compact one. [ABSTRACT FROM AUTHOR]

Several samples of Zn-Sb alloys, composed with β-ZnSb and Zn phases, were prepared by solidification under high magnetic fields (HMFs). The microstructure evolution and thermoelectric (TE) properties of the alloys were then investigated. Zn phase precipitated as strip and presented reticulation structure in the samples without HMFs. When the HMFs were imposed, Zn became disperse and the strip of Zn became thinner and shorter. In addition, the c-axis of Zn crystals showed a tendency to orientate toward the direction perpendicular to the magnetic field direction. The samples prepared under HMFs had higher resistivity and Seebeck coefficient and lower thermal conductivity. When compared to the solidified samples without HMFs, the application of 8.8 T of HMF increased the maximum figure of merit 3.7 times. In addition, the relationship between microstructure and TE properties was also analyzed. [ABSTRACT FROM AUTHOR]

In present studies, l-arginine doped zinc thiourea chloride (LAZTC) crystal has been grown by slow solution evaporation technique. The cell parameters of LAZTC crystal were determined using the single crystal X-ray diffraction technique. The incorporation of l-arginine in ZTC has been confirmed by means of Fourier transform infrared analysis. The high optical transparency of the grown crystal has been examined under the UV-visible study. The wide optical band gap of LAZTC crystal is found to be 5·25 eV. The photoluminescence study of grown crystal has been investigated in the range of 300 to 700 nm. The negative photoconducting nature of LAZTC crystal has been investigated by means of photoconductivity studies. Thermal stability of LAZTC crystal was evaluated by thermogravimetric and differential thermal analysis. The dielectric measurements confirmed the lower dielectric characteristics of LAZTC crystal. [ABSTRACT FROM AUTHOR]

In this paper, the formation of zinc dendrites at the strip edge of an industrial electrogalvanizing line was studied. For that purpose, a rotating washer electrode was designed to reproduce the hydrodynamic conditions and the current density distribution found in the industrial process. Polarization curves were recorded at different rotation speeds in order to investigate the electrokinetic behavior of the cathodic process. The induction time for dendritic growth was estimated for different overpotential values and the existence of a minimum overpotential below which dendrites do not grow was confirmed. Dendrite precursors on the edge of the washers were well characterized and its birth and precise location were studied. The general model of disperse and dendritic metal electrodeposit formation derived by Popov et al. was used to explain the effect of electrolyte zinc concentration, rotation speed of the cathode, electrolyte temperature and edge roughness on the size and morphology of dendrites. The results showed that this theory provides an accurate description of the phenomenon even for non-stationary electrodes, which have not been extensively studied so far. The experimental setup proved to be a powerful means to study the formation of dendritic growth of zinc crystals on the edges of steel strip and is well suited to characterize other metals that produce this type of defect. [ABSTRACT FROM AUTHOR]

Fluorescence of zinc(II) bis(dipyrrolylmethenates) [Zn2L2] is very sensitive to the medium polarity. Fluorescence quantum yield (f) of [Zn2L2] reaches 0.99 in nonpolar media and close to zero in the electron donor solvents (amines, alcohols and other). Fluorescence quenching may be caused by the additional coordination of the electron donor molecules on the zinc atoms with formation of stable supramolecular structures [Zn2L2(Solv)n]. For the confirming this assumption, the samples of the crystal solvates of 2,2'-, 2,3'- and 3,3'-bis(dipyrrolylmethenato)zinc(II) with N,N-dimethylformamide were obtained by slow crystallization. Spectroscopic studies showed that the quantum yield of crystal solvates in cyclohexane solutions is noticeably lower than f for corresponding complexes [Zn2L2]. The thermal dissociation processes of crystal solvates in an argon atmosphere have been investigated. It is shown that helicates of the zinc(II) with decamethylsubstituted 2,2'-, 2,3'- and 3,3'-bis(dipyrrolylmethenes) form with DMF stable supramolecular complexes of the composition [Zn2L2(DMF)2]. Crystal solvates [Zn2L2(DMF)2] are stable up to a temperature below ~100°C in an inert argon atmosphere and the values of the enthalpies of their thermal destruction process are 88-143kJ/mol. The obtained results are of interest for the development on the basis of [Zn2L2] of the fluorescent sensors of the electron donor molecules. [ABSTRACT FROM AUTHOR]

Highlights: [•] Dichlorobis (l-proline) zinc (II) (DCBPZ) is an organometallic compound. [•] DCBPZ single crystal was grown by slow evaporation technique. [•] Thermal stability and meting point were analyzed using thermal studies. [•] Highly optical transparency was observed in the crystal. [•] The NLO result obtained show that the SHG efficiency of DCBPZ is found to be twice that of KDP. [ABSTRACT FROM AUTHOR]

The motion of grain boundaries in zinc bicrystals (99.995 %) driven by the 'magnetic' driving force was measured. An in situ technique for observations and continuous recording the boundary migration was applied. Planar symmetrical and asymmetrical $$ \left\langle {10\overline{1} 0} \right\rangle $$ tilt grain boundaries with rotation angles in the range between 60° and 90° were studied. The boundary migration was measured in the temperature regime between 330 and 415 °C. The mobility of $$ \left\langle {10\overline{1} 0} \right\rangle $$ tilt boundaries in zinc and its temperature dependence were found to depend on the misorientation angle and the inclination of the boundary plane. An application of a magnetic field during the annealing of cold rolled (90 %) zinc-1.1 % aluminum alloy sheet specimens substantially affected the texture and microstructure evolution. This effect is attributed to the additional magnetic driving force for grain growth arising due to the magnetic anisotropy of zinc. [ABSTRACT FROM AUTHOR]

We discover the detailed atomic structure of-MgZnY, a stable decagonal quasicrystal alloy of the layered Frank–Kasper type, and related phases, using the ‘tiling and decoration’ approach. The atoms have invariable sites in the rectangle and triangle tiles of a 10-fold-symmetric planar tiling. To discover the lowest-energy structures, we combine the methods of density functional theory (DFT) total energy calculations, empirical oscillating pair potentials (fitted to DFT), fitting effective Hamiltonians for tilings, and discovering optimum tiling structures using a nonlocal tile-reshuffling algorithm. We find a family of almost stable binary compounds with varying composition, including the decagonal quasicrystal and the known MgZn; in addition, we show the ternary versions can be stable:-MgZnY at high temperature, and-MgZnSc even at. [ABSTRACT FROM AUTHOR]

Highlights: [•] Caesium(I)-doping on the properties of bis(thiourea)zinc(II) chloride is reported. [•] Slight shifts in vibrational pattern of doped specimen is observed. [•] Interestingly alkali metal doping influences the band gap energy of BTZC. [Copyright &y& Elsevier]

Abstract: In this study, we characterize the relative crystal quality of zinc oxide (ZnO) synthesized at various temperatures via photoluminescence (PL) measurements. By varying the oxidation temperature during the growth process, different sample morphologies arise. These structural differences cause changes in the PL spectra which allow us to gain insight into the crystal purity. We employ three independent spectroscopic methods to examine ZnO prepared with various morphologies; time-integrated PL, random lasing, and time-resolved PL. As a result of the impurity band being resonant with the two-photon absorption (2PA) range, multifold enhanced 2PA is observed and the 2PA coefficient is measured to be 2500cm/GW for tetrapod ZnO at 613nm. [Copyright &y& Elsevier]

Abstract: A critical review is proposed of the different techniques of bulk growth of ZnO crystals for their use as a substrate in the homoepitaxial growth of this attractive compound. The crystals are assessed from their structural and electrical properties and from the structural properties and purity of homoepitaxial films grown on them by various techniques such as plasma-assisted molecular beam epitaxy, pulsed laser deposition, magnetron sputtering, chemical vapor deposition, metalorganic chemical vapor epitaxy, liquid phase epitaxy. [Copyright &y& Elsevier]

Solid-state physics and quantum electrodynamics, with its ultrarelativistic (massless) particles, meet in the electronic properties of one-dimensional carbon nanotubes, two-dimensional graphene or topological-insulator surfaces. However, clear experimental evidence for electronic states with a conical dispersion relation in all three dimensions, conceivable for certain bulk materials, is still missing. Here, we study a zinc-blende crystal, HgCdTe, at the point of the semiconductor-to-semimetal topological transition. For this compound, we observe three-dimensional massless electrons, as certified from the dynamical conductivity increasing linearly with the photon frequency, with a velocity of about 106 m s−1. Applying a magnetic field B results in a -dependence of dipole-active inter-Landau-level resonances and spin splitting of Landau levels also following a -dependence-well-established signatures of ultrarelativistic particles but until now not observed experimentally in any solid-state electronic system. [ABSTRACT FROM AUTHOR]

The paper presents the investigation of the relation between the acoustic emission (AE) and instability of plastic deformation type Portevin-Le Chatelier (PLC) of single-phase brass CuZn30 monocrystals with crystallographical orientation [1¯3 9]. The monocrystals have been investigated applying the method of free compression at a constant strain rate and the temperature within the range from 200°C to 400°C, simultaneously recording PLC phenomenon by means of acoustic emission. During hot axial compression tests the correlation between work-hardening curves σ - ε, which display PLC effect and characteristic of acoustic emission signals has been found. Moreover, it was proved that in the range of the PLC effect, the acoustic signal is an impulse a character of cyclic repeatability, distinctly correlated qualitatively with the stress oscillations on the curves σ - ε. The analysis of the obtained results leads to the conclusion that in the tested monocrystals the effect PLC is probably controlled by complex processes similar to the phenomenon of dynamic strain ageing (DSA), which are described by diffusion models. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mixed crystal K2Zn0.84Mn0.16(SO4)2⋅6H2O belongs to monoclinic system with P21/c space group. [•] High-resolution XRD reveals the presence of vacancy type defects in the mixed crystal. [•] Co-existence of Zn and Mg in the mixed crystal is confirmed by single crystal XRD, EDS and AAS. [ABSTRACT FROM AUTHOR]

• The growth conditions to produce a ZnWO 4 :Sm single crystals were determined. • The Sm3+ segregation coefficient in the ZnWO 4 single crystal was estimated to be 0.023. • The effect of Sm3 + segregation on the ZnWO 4 crystal lattice parameters has been investigated. • ZnWO 4 :148,149Sm crystals were obtained following the established growth technique. The growth conditions to produce a high quality ZnWO 4 :Sm single crystals by the Czochralski method were determined in this work. The role of the Sm impurity in the formation of bubbles in a ZnWO 4 single crystal is discussed. The Sm3+ ions segregation coefficient in the ZnWO 4 single crystal was estimated to be 0.023. The effect of non-isomorphic substitution of Sm3 + for Zn2 + ions on the ZnWO 4 crystal lattice parameters has been investigated. The X-ray luminescence spectra of ZnWO 4 :Sm3+ crystals are discussed. Two ZnWO 4 crystals doped with samarium enriched in 148Sm and 149Sm isotopes were obtained following the established growth technique, which demonstrates its feasibility and reliability for production of detector for rare nuclear processes studies. [ABSTRACT FROM AUTHOR]

• Stability of growth interface near the end of the growth is disturbed due to lack of feed material. • Interface instability leads to trapping of molten zone in small pockets which transforms into Te inclusions. • Towards the end of the growth, Zn phase is separated, solidifies and grow inside CdZnTe crystal. • Lack of feed material in THM growth lead to growth of low quality CdZnTe crystal. Growth of CdZnTe crystals by Travelling Heater Method (THM) is widely investigated by different groups. Interface shape and stability are critical parameters for the successful growth of high-quality CZT crystals. Even though interface stability could be achieved for a significant portion of the CZT ingot, the situation towards the end of the growth is not well studied and understood. In this study, interface stability and the change of crystal quality towards the end of the growth are examined. The change of the interface shape and formation of large Te inclusions are observed. Moreover, towards the end of the growth, phase separation and formation of a new zinc-based phase are detected with a needle-like structure. The decrease of crystal quality and evolution of the CZT ingot towards the end of the growth are summarized. [ABSTRACT FROM AUTHOR]

This paper presents a new robust large-strain (LS) elasto-viscoplastic (EVP) formulation based on Fast Fourier Transforms (FFTs) for the prediction of the micro-mechanical response and microstructure evolution of polycrystalline and multiphase materials, with emphasis on the effect of strong crystallographic and/or morphologic anisotropy on localization of plastic deformation. The novel LS-EVPFFT formulation allows treatment of complex initial geometries and large deformations considering three grids of material points: a regular grid in the reference configuration, where FFTs can be performed; an irregular grid in the initial configuration, created by applying a stress-free displacement field to the reference regular grid; and an irregular grid in the current configuration, undergoing large strains and rotations as the material is loaded. Further numerical stability of the new formulation also required the use of a novel expression for the discrete modified Green's operator, which reduces spurious field oscillations. After presenting and validating the new formulation by comparison with pre-existing implementations and analytical solutions, LS-EVPFFT is applied to the prediction of slip and kink bands formation in polycrystalline columnar ice, and kink bands in single crystal zinc wires, showing good agreement with classic experiments. Finally, the model is used to study kink band formation during compression of Cu–Nb nano-metallic laminates (NMLs), in which accurate treatment of the complex geometry associated with the tortuosity of interfaces and large deformations become critical, showing consistency with corresponding micropillar experiments. • A new finite-strain elasto-viscoplastic FFT formulation for polycrystals is presented. • The model allows treatment of complex initial geometries and large deformations. • Predictions show the strong effect of anisotropy on localization of plastic deformation. • Kink band formation in ice and zinc wires is predicted, in agreement with experiments. • The model reproduces the complex localization behavior of Cu–Nb nanometallic laminates. [ABSTRACT FROM AUTHOR]

The as-precipitated sulfate-intercalated layered double hydroxide of Zn and Al crystallizes in the structure of the 3R1 polytype. On hydrothermal treatment, this 3R1 polytype transforms into the somewhat rare 3H and 3R2 polytypes at different temperatures. Observation of the 3R2 polytype distinct from the 3R1 polytype is evidence for the lack of cation ordering in the [Zn-Al-SO4] system. The layered double hydroxide of Zn and Cr (polytype, 1H) on hydrothermal treatment in mother liquor yields a cation-ordered phase also having the structure of the 1H polytype. Direct evidence of cation ordering is found by the appearance of weak supercell reflections corresponding to a = v3 × ao (ao is the a parameter of the cation-disordered phase). The same precursor under other conditions yields the cation-disordered 3R1 polytype. In this work, the structures of both the cation-ordered and the cation-disordered phases with similar states of hydration are refined and compared. [ABSTRACT FROM AUTHOR]

The structure of cubic ZnFeSSe (0 ≤ x ≤ 1) crystals obtained by vapor-phase chemical transport has been investigated by thermal-neutron diffraction. The diffraction patterns of these crystals are found to exhibit previously unknown diffuse-scattering effects related to local static atomic displacements in the metastable fcc lattice. It is substantiated that the tendency to form polytypes, which is characteristic to a greater extent of zinc sulfide, can be a key factor of instability in the lattice of compounds belonging to the series of anion-substituted solid solutions under study. [ABSTRACT FROM AUTHOR]

Temperature changes in the components of complex dielectric tensor were studied in triglycine–zinc chloride crystal in the range 80–300 K. The real part of permittivity in the [001] direction shows a big jump at 234 K. The imaginary part of all dielectric components has small dispersion above this temperature. Possible phase transition in triglycine–zinc chloride crystal has been discussed. Results of measurements performed in isothermal conditions at 82 K reveal a slow rise in permittivity to its initial value measured above 234 K. This process depends on the frequency of measuring field. The JMA analysis is applied to determine the Avrami parameter. [ABSTRACT FROM AUTHOR]

The shape of a 90° ⟨112⟩ tilt boundary in bismuth and a boundary in zinc bicrystals was analyzed, which had developed during annealing at elevated temperatures when the boundary had migrated due to the magnetic free energy density difference across the boundary while the boundary was fixed on the lateral sample surfaces. After annealing in an external magnetic field the 90°⟨112⟩ boundary in bismuth became faceted. This evidenced the pronounced anisotropy of boundary energy with respect to its inclination. The random (non-tilt) boundary in the Zn bicrystal assumed a curved shape after magnetic annealing. Evaluation of the curvature of the boundary segments with the highest constant curvature permitted estimation of the upper limit of the energy of differently inclined boundary sections in Zn: 0.27 and 0.41 J m−2. [ABSTRACT FROM PUBLISHER]

Abstract: ZnO of different morphologies with controlled size and aspect ratio (l/d) such as dumbbell-like microrods, thick nanowires and thin nanowires were prepared by a hydrothermal method. Possible mechanisms for the formation of ZnO crystals with the different morphologies were discussed. Strong violet photoluminescence bands at∼413nm (3.0eV) without band edge emission were observed from the dumbbell-like ZnO microrods and thick nanowires. Correspondingly, the thin nanowires showed a weak shoulder UV photoluminescence band at∼390nm. Such result indicates that the photoluminescence properties could be improved by the morphologies or aspect ratio (l/d) and the potential fabrication violet-light-emitting devices. [Copyright &y& Elsevier]

Abstract: Nano-crystalline zinc-substituted cobalt ferrite powders, Co1−x Zn x Fe2O4 (x =0, 0.25, 0.5, 0.75 and 1), have been synthesized by the combustion route. The structural, morphological and magnetic properties of the products were determined and characterized in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometer (VSM). X-ray analysis showed that the samples were cubic spinel. The increase in zinc concentration resulted in an increase in the lattice constant, unit cell volume, X-ray density, ionic radii, the distance between the magnetic ions and bond lengths on tetrahedral sites and octahedral sites of cubic spinel structure. Opposite behavior was observed for the average crystallite size of the as synthesized solids. The variation of saturation magnetization (M s) value of the samples was studied. The maximum saturation magnetization value of the Coo.25Zn0.75Fe2O4 sample reached 76.87emu/g. The high saturation magnetization of these samples suggests that this method is suitable for preparing high-quality nano-crystalline magnetic ferrites for practical applications. [Copyright &y& Elsevier]

Abstract: Cu(In,Ga)Se2 (CIGS) surface was modified with Zn doping using a magnetron sputtering method. CuInGa:Zn precursor films targeting a CuIn0.7Ga0.3Se2 stoichiometry with increasing Zn content from 0 to 0.8at% were prepared onto Mo-coated glass substrates via co-sputtering of Cu–Ga alloy, In and Zn targets. The CuInGa:Zn precursors were then selenized with solid Se pellets. The structures and morphologies of grown Zn doped CIGS films were found to depend on the Zn content. At zinc doping level ranging between 0.2 and 0.6at%, the Zn doping improved the crystallinity and surface morphology of CIGS films. Compared with the performance of the non-doped CIGS cell, the fabricated CIGS solar cell displayed a relative efficiency enhancement of 9–22% and the maximum enhancement was obtained at a Zn content of 0.4at%. [Copyright &y& Elsevier]

An enhanced valence force field model for zinc-blende crystals is developed to provide a unified description of the isothermal static and dynamical lattice properties of gallium arsenide. The expression for the lattice energy includes a second-nearest-neighbor coplanar interaction term, the Coulomb interaction between partially charged ions, and anharmonicity corrections. General relations are derived between the microscopic force constants and the macroscopic elastic constants in zinc-blende crystals. Applying the model to gallium arsenide, parameter sets are presented that yield quantitative agreement with experimental results for the phonon dispersion, elastic constants, sound velocities, and Grüneisen mode parameters. [ABSTRACT FROM AUTHOR]

Abstract: A nano-island array of approximately 7-nm-diameter Zn single crystals embedded in a SiO2 nanowire was created by using electrospinning and electron-beam irradiation. Bright-field transmission electron microscopy (TEM) images, high-resolution TEM (HRTEM) images, energy dispersive spectroscopy (EDS), and fast-Fourier-transformed electron diffraction patterns showed that Zn nanocrystals were created inside the SiO2 nanowire. The formation mechanisms of Zn nanoparticles embedded in a SiO2 nanowire due to the decomposition of ZnO and SiO2 nanoparticles are described on the basis of the HRTEM images and the EDS profiles. [Copyright &y& Elsevier]

Abstract: In this study, Cd1−x Zn x Te crystals, with x=0.20, were grown unseeded by closed-ampoule vertical directional solidification (Bridgman) technique under controlled Cd over-pressures. CdZnTe crystals of high electrical resistivity have been reproducibly obtained with the In dopant concentration of 4–6ppm, atomic and a Cd reservoir temperature between 785 and 825°C. A combination of three process modifications have contributed to the accomplishment: (1) homogenizing the ampoules of starting materials under the vacuum environment to minimize contamination, (2) performing growth under controlled Cd over-pressures with the optimal In dopant, and (3) controlling post-growth cooling procedures to maintain uniformity of electrical properties over the crystal. [Copyright &y& Elsevier]

Abstract: Pulse electrodeposition was to produce nanocrystalline (nc) zinc from alkaline non-cyanide electrolyte with primary and secondary additives. The combined effect of pulse parameters (ON-time (T ON), OFF-time (T OFF), pulse peak current density (I P)) and additives on the corrosion properties (evaluated using electrochemical techniques) of zinc electrodeposits are elucidated in terms of surface morphology (using scanning electron microscope), topography and root mean square (RMS) roughness (using atomic force microscope), crystallite size, its orientations and relative texture co-efficient (RTC, %) were evaluated using X-ray diffraction. The corrosion resistance of zinc electrodeposits obtained at constant T ON and I P enhanced (i.e., low I corr and high R ct values) with increased T OFF. At constant T OFF and I P, the I corr values increased and R ct values decreased with T ON while the former decreases and latter increases with I P at constant T ON and T OFF. The inclusion of primary and secondary additives into the electrolyte produced nc zinc electrodeposits at 5Adm−2, showed enhanced protective properties (I corr—16μAcm−2 and R ct—481.8Ωcm−2). Fine grained due to high negative overpotential, reduced roughness and higher percentage of basal plane [00.2] orientation have major impact for the enhanced corrosion resistances. [Copyright &y& Elsevier]

Two new complexes constructed by 1,4-phenylenediacetic acid (H2PDA) and 2,2'-bipyridine (2,2'-bpy), namely [Cu(PDA)(2,2'-bpy)]·5H2O (1) and [Zn2(PDA)(2,2'-bpy)2Cl2] (2), have been synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR, and UV-Vis spectrum. Single-crystal X-ray diffraction reveals that they both crystallize in the triclinic space group of P-1. In complex 1, the Cu atom is hexa-coordinated and each asymmetric unit contains five uncoordinated water molecules that form a water cluster (H2O)10 with their symmetric equivalent. Complex 2 is a simple dimer and the Zn atom is penta-coordinated. Both in complex 1 and 2 there are π-π stacking interactions. [ABSTRACT FROM AUTHOR]

A new zinc coordination polymer, [Zn(atda)(4,4'-bipy)]n (H2atda = (4-amino-1,2,4-triazole-3,5-diyldithio)diacetic acid, 4,4'-bipy = 4,4'-bipyridine), was synthesized by rheological phase reaction method and characterized by elemental analysis, IR, UV and single-crystal X-ray diffraction. The results reveal that it possesses three-dimensional (3D) solid-state structure. The Zn(II) inos are interlinked by bridging of atda2 ligands and 1D [Zn(atda)]n double chains are constructed, which are further connected together by the coordination of 4,4'-bipy molecules and 2D double layered structure are generated. Hydrogen-bonding interaction exists between the layers, resulting in the formation of 3D supramolecular structure. In addition, thermal stability and fluorescent property were studied. [ABSTRACT FROM AUTHOR]

Magnetically driven migration of planar tilt grain boundaries with various misorientations in high purity zinc bicrystals was measured in situ by means of a specially designed polarization microscopy probe. The absolute grain boundary mobility and its temperature dependence were measured in the regime between 330 and 415°C. The results revealed that there is a pronounced misorientation dependence of grain boundary mobility in the investigated angular range. The migration activation enthalpy was found to vary between 1.18 and 2.15eV. [Copyright &y& Elsevier]

Abstract: Nanocrystalline zinc substituted nickel ferrites, Ni1−x Zn x Fe2O4 (0.0≤ x ≤1.0) have been prepared by citrate gel auto-combustion method. The effect of zinc ion content on structural, electrical transport and magnetic properties has been studied. The X-ray diffraction (XRD) pattern revealed that, all the compositions possess single-phase spinel structure. The nano-sized grain structure formation was confirmed by transmission electron microscopy (TEM). The dc electrical resistivity shows the samples are semiconducting in nature. The magnetic measurements showed that the composition Ni0.6Zn0.4Fe2O4 has maximum saturation magnetization (M s) while high coersivity (Hc) for ZnFe2O4. Thermoelectric power measurement study showed that the compounds, with x ≤0.4 are p-type and for x >0.4 behaves n-type conduction mechanism. [Copyright &y& Elsevier]

The article discusses effect of galvanization on the morphology of various coating layer obtained in hot-dip baths with alloys of metals like aluminum, silicon and mercury. It has been stated that galvanized sheets present metallic brightness, light silver color, with dendrite zinc crystals of different shapes and sizes according to the chemical composition of the hot-dip bath. It has been stated that micro-alloying elements can enhance the surface quality of the galvanized steel by providing uniformity, texture and luminosity. It has been stated that the surface can acquire different types of metallic coatings depending on the combination of micro-alloying elements.

A series of unique morphologies of ZnO were synthesized by a simple mild solvothermal process using equimolar of Zn(NO3)2/Zn(AC)2–hexamethylenetetramine (HMT) acting as precursors and ethylene glycol (EG) and triethylamine (TEA) as the dispersant and surfactant additive, respectively. When the as-prepared particles were further treated in 0.02 M HMT solution for such a long time as 72 h, screw-like and rose-like crystals with three-dimensional and developed structure could be formed. The deNO x photocatalytic activity was characterized and the analysis results showed that the modified ZnO crystals possessed a three-dimensionally developed structure and had higher deNO x photocatalytic activity compared to that of the as-prepared untreated ZnO. [ABSTRACT FROM AUTHOR]

Abstract: Highly oriented and densely packed one-dimensional (1D) polycrystalline Zn nanorods were fabricated on zinc plate without any catalyst at room temperature by bombardment with obliquely incident Ar+ ion via ion irradiation method. The sputtered surfaces were fully covered with Zn nanostructures with diameter and the length around 60nm and 1.3μm, respectively, confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The crystal orientation of the Zn plate was investigated by electron back scattering pattern method (EBSP). The numerical density and morphology of Zn nanostructures (nanoneedle or nanorods) were found to be 2.1×106 to 9×106/mm2 depending upon the crystal orientation and the atomic density on different crystallographic faces. () faces of Zn polycrystal tended to form more dense nanostructures compared to () faces. This is because of lower atomic density on () faces in comparison with () faces. This indicates that lower atomic density on any crystallographic faces is favorable to form nanostructure of higher density. The outstanding feature of this growth technique is that it provides a new direction for the controllable growth of desired nanostructures of variable density at room temperature without any catalyst. These well-aligned arrays of Zn nanorods/nanoneedle might be a promising material for the future application in nanodevices. [Copyright &y& Elsevier]

Abstract: The effects of the presence of additives like lead and tungstate ions in flowing alkaline zincate solutions on suppressing spongy zinc electrogrowth are examined. The results show that the two additives with optimal concentrations in flowing electrolytes can suppress spongy zinc initiation and propagation. And, the two additives can bring about more uniform and compact deposits and, thereby, reduce spongy zinc growth. The influence of lead and tungstate ions on the zinc deposition/dissolution is evaluated by cyclic voltammetry. It also shows that the addition of the two additives is largely a blocking action, and the co-deposition of lead and zinc ions may occur. The performance of the zinc-air flow battery with zinc regeneration electrolysis is determined. It shows that by the addition of 0.6M Na2WO4 or 10−4 M to 10−3 M lead, compact or mixed compact–spongy zinc deposits are created and the favorable charge/discharge performance of the battery is achieved with an energy efficiency of approximately 60%. [Copyright &y& Elsevier]

Abstract: ZnO thin films were deposited by capillaritron ion beam sputtering deposition. The crystalline quality, stoichiometry and photoluminescence properties of as-deposited and annealed ZnO thin films were studied. The as-deposited ZnO films show no preferred crystallographic orientations while annealed films exhibit a strong single ZnO (002) diffraction peak at 34.50°. The stoichiometry of ZnO films were found to be dependent on both beam energy and annealing conditions that the atomic percent ratio of Zn/O can be controlled between 0.95 and 1.10. ZnO films deposited with 4keV ion beam and annealed at 800°C in oxygen shows the lowest defect related deep level visible emission, while 80% of oxygen atoms are still located in fully oxidized stoichiometric ZnO matrixes. [Copyright &y& Elsevier]

Abstract: Cd1− x Zn x O nanocrystalline thin films with rock-salt structure were obtained through thermal decomposition of Cd1− x Zn x O2 (x =0, 0.37, 0.57, 1) thin films which were electrodeposited from aqueous solution at room temperature. X-ray diffraction results showed that the Zn ions were incorporated into rock salt-structure of CdO and the crystal lattice parameters decreased with the increase of Zn contents. The bandgaps of the Cd1− x Zn x O thin films were obtained from optical transmission and were 2.40, 2.51, 2.63 and 3.25 eV, respectively. [Copyright &y& Elsevier]

Abstract: Pulse electrodeposition was used to synthesize nanocrystalline (NC) zinc coatings from citric acid bath. The electrochemical behaviour of the NC zinc coatings was investigated by using potentiostatic and potentiodynamic polarization methods in 0.5mol/L NaCl (pH=12) solution and compared with that of cast zinc. Pitting corrosion behaviour was characterized by pitting potential, induction time and stable pit growth rate which were analyzed according to statistical method. The results showed that nanocrystallization increased the sensitivity of Epit refer to potential sweep velocity, changed the type of the pit generation from B1 (parallel) to B2 (series), accelerated the pitting initiation process and inhibited the stable pit growth process of NC zinc. [Copyright &y& Elsevier]

Abstract: Single-phase Zn1− x Co x O (x=0.02, 0.04) powders were synthesized by a simple co-precipitation technique. X-ray diffraction analysis reveals that the Co-doped ZnO crystallizes in a wurtzite structure. The lattice constants of Co-doped ZnO powders decrease slightly when Co is doped into ZnO. Optical absorption spectra show a decrease in the bandgap with increasing Co content and also give an evidence of the presence of Co2+ ions in tetrahedral sites. Raman spectra indicate that Co doping increased the lattice defects and induced another Raman vibration mode around at 538cm−1, which is an indicator for the incorporation of Co2+ ions into the ZnO host matrix. Magnetic measurement reveals that the Zn1− x Co x O (x=0.02, 0.04) powders clearly exhibit room-temperature ferromagnetic behavior, which makes them potentially useful as building components for spintronics. [Copyright &y& Elsevier]

The single-crystal n-type and p-type ZnO nanowires (NWs) were synthesized via a chemical vapor deposition method, where phosphorus pentoxide was used as the dopant source. The electrical and photoluminescence studies reveal that phosphorus-doped ZnO NWs (ZnO:P NWs) can be changed from n-type to p-type with increasing P concentration. Furthermore, we report for the first time the formation of an intramolecular p-n homojunction in a single ZnO:P NW. The p-n junction diode has a high on/off current ratio of 2.5 × 103and a low forward turn-on voltage of ∼1.37 V. Finally, the photoresponse properties of the diode were investigated under UV (325 nm) excitation in air at room temperature. The high photocurrent/dark current ratio (3.2 × 104) reveals that the diode has a potential as extreme sensitive UV photodetectors. [ABSTRACT FROM AUTHOR]

Abstract: ZnO thin films were prepared by thermal oxidation of Zn metal at 400°C for 30 and 60min. The XRD results showed that the Zn metal was completely converted to ZnO with a polycrystalline structure. The sensors had a maximum response to H2 at 400°C and showed stable behavior for detecting H2 gases in the range of 40 to 160ppm. The film oxidized for 60min in oxygen flow exhibited higher response than that of the 30min oxidation which was approximately 4000 for 160ppm H2 gas concentration. The sensing mechanism was modeled according to the oxygen–vacancy model. [Copyright &y& Elsevier]

Abstract: The microstructural characterization of Ga-doped (5at.%) ZnO thin film was conducted by a transmission electron microscopy study. The atomic arrangement of Ga-doped ZnO having an wurtzite structure was identified by the experimental HRTEM and Fourier filtered images as well as the electron diffractions. As a result, we have revealed that the orientation and defect density of Ga-doped ZnO thin films were greatly influenced by the deposition temperature, resulting in the variation of electrical property. In other words, the tendency forming a c-axis oriented texture grows up and the defects such as dislocations and stacking faults decrease, as the temperature of sputtering deposition increases. Consequently, the electrical properties of Ga-doped ZnO thin films can be controlled by the deposition temperature directly related with the defect density. [Copyright &y& Elsevier]

Abstract: Zinc oxide has a variety of applications in catalysis both as support and as active phase for hydrogenation or dehydrogenation reactions. This review provides an overview of the surface chemistry of ZnO nanoparticles concerning the interaction with small molecules such as CO, CO2, H2, H2O, and CH3OH, which are relevant for the catalytic synthesis of methanol and the water gas shift reaction. These interactions were studied by combining surface-sensitive methods such as infrared spectroscopy, temperature-programmed desorption, and adsorption calorimetry. A thorough understanding of the processes occurring on the different exposed facets of the ZnO particles in an atmosphere of reactive gases was achieved based on the comparison with results obtained in ultra-high vacuum with single-crystalline surfaces, i.e. under well-defined conditions, and by using first-principles calculations. [Copyright &y& Elsevier]

Abstract: Large-scale uniform nutlike ZnO microcrystals are successfully synthesized via a facile hydrothermal process at low temperature (95 °C). The structure and morphology of the ZnO products are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results reveal that the as-prepared ZnO products have average length of 2.2 µm and diameter of 1.8 µm, possessing a single crystal wurtzite structure. The possible formation mechanism of nutlike microcrystals is proposed. The samples exhibit excellent ethanol sensing properties at the operating temperature of 250 °C detecting ethanol as low as 1 ppm. [Copyright &y& Elsevier]

Abstract: ZnO thin film was prepared via evaporation of Zn metal on a glass sheet following by calcination (oxidation) process. The influences of calcination parameters such as temperature and time on the surface morphology and phase structure of ZnO films were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The analysis of XRD patterns indicated that the growth of ZnO nano-structure was controlled by calcination time and temperature. Optimum ZnO nano-fibers can be formed uniformly after 2 h of oxidation at 550 °C. Nanostructured ZnO catalyst exhibited a significantly greater superiority for the photodegradation of 2,4,6-Trichlorophenol (TCP) as a model pollutant in water over photolysis via irradiation with UV of 254 nm wavelength. The role of ZnO catalyst is discussed and the chemical composition of degradation products and intermediates are identified. [Copyright &y& Elsevier]

Abstract: The metastable phase (phase 1) Zn(OH)2(tp)2 (tp=C8H4O4 2−) was found to be an intermediate forming during the hydrothermal synthesis of Zn3(OH)4tp (phase 2). Its structure has been determined ab initio from synchrotron powder diffraction data and refined with the Rietveld method: space group P21/c, a =3.48856(2)Å, b =5.84645(2)Å, c =22.1331(1)Å, β =103.46(1)°, D x =2.488g/cm3, R p =0.10, R B =0.095 (402 independent reflections). The structures of the two analogues were compared. Whereas a mixed coordination of the zinc atoms was found in phase 2, phase 1 exhibits only penta-coordinated Zn(II). Moreover, different optical properties were observed, Zn2(OH)2(tp) showing photoluminescence at 378nm under λ ex =316nm. [Copyright &y& Elsevier]

Abstract: Via a simple aqua-solution hydrothermal route, uniform ZnS nanorod arrays were fabricated upon pulse-plating Zn nanocrystallines. Particularly, low temperature (95°C) and short time (1h) were employed in the hydrothermal reaction. ZnS nanorods were found to be grown along certain Zn crystalline direction. Control experiments which were performed by replacing Zn nanocrystallines with Zn plate found no one-dimensional ZnS nanostructure on the substrate. Therefore, it was proposed that pulse-plating Zn nanocrystallines acted as both reactant and seed during the hydrothermal process. ZnS nanorod arrays could be theoretically fabricated on almost any raw base plate as long as Zn nanocrystallines could be pulse-plated on the plate. The ZnS nanorod arrays with high length-to-diameter ratio were expected to be a potential candidate for future field-emission devices. [Copyright &y& Elsevier]