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Microwave irradiation has exceptional advantages for materials preparation and extractive metallurgy with its unique and distinguished characteristic of volumetric and selective heating. Here, we design a new experimental apparatus and construct an efficient microwave heating reaction system between MgO-CaO and Al-C powders to prepare magnesium using microwave heating method by the reasonable addition of graphite powders into the reaction sample at atmospheric pressure. First, the effect of ball milling on the microwave heating characteristics of the reaction sample was investigated by using Material studio software. Then, the effects of ball milling, forming pressure of sample and composition of reducing agents on the reduction ratio of MgO were studied as well. Furthermore, the sample and reduzates were characterized by XRD, SEM and EDS; the reaction mechanism reinforced by microwave irradiation was revealed as well. It was found that the reaction samples were rapidly heated up to 1323 K, when the microwave irradiation time is about 1000 s. Moreover, the CaC2 phase was formed during the reduction of MgO, which could improve the reduction efficiency of MgO. These results show that microwave irradiation has a good reinforcing effect on the reaction, and our results could offer new insight into high-efficiency magnesium producing. [ABSTRACT FROM AUTHOR]

A novel ionic responsive Schiff base organic gelator was successfully designed and synthesized. The solvent selection experiment showed that the gelator showed good thermoreversible gelator behavior in aniline, valerate alcohol and isopropyl alcohol. FT-IR studies have shown that C=O and N–H of molecules participate in the formation of intermolecular hydrogen bonds, thus promoting the formation of gelator states. The XRD and SEM results show that the molecules self-assemble in the dry gelator to form the entangled network structure. In addition, the fluorescence spectrum test of gelling agent G showed that gelling agent G could specifically recognize Cu2+. Gelator G has good selectivity, low detection limit (2.92 × 10–8 M) and high sensitivity, which can be applied to the detection of Cu2+ in biology, environment and other fields. The results show that gelator G has broad application prospects in materials science, chemistry, biomedicine and other fields. It also confirms that benzopyran-derived hydrazone Schiff base compounds have far-reaching research significance. [ABSTRACT FROM AUTHOR]

In general, β-Ga2O3 films with (2¯01) out-of-orientation have been widely obtained and reported on (0001) sapphire substrates by various growth methods. In this paper, the unusual (3¯10)-oriented β-Ga2O3 films have been epitaxially grown on (0001) sapphire substrates with high crystal-quality under Ga-rich conditions by halide vapor phase epitaxy (HVPE). The out-of-plane epitaxial relationship as (3¯10) β-Ga2O3//(0001) α-Al2O3 has been confirmed by XRD and HRTEM analysis. Under most growth conditions, β-Ga2O3 films exhibit the coexistence of (3¯10) and (2¯01) out-of-plane orientation domains, and increasing the growth temperatures and HCl flow-rates can enhance the growth of (3¯10)-oriented β-Ga2O3. Off-angled (0001) sapphire substrates with off-angles (Δa) toward 〈112¯0〉 have been introduced to control the in-plane domains. It was indicated that the (2¯01)-oriented domains have been gradually eliminated with increasing the off-angles, and pure (3¯10)-oriented β-Ga2O3 films with the best crystal quality reported so far have been obtained while the off-angle was ∼7°. The decrease of the domain boundaries and defects caused by the in-plane rotational domains have led to the improvement of the crystal quality of the as-grown films. [ABSTRACT FROM AUTHOR]

One-step adsorption separation of C2H4 from ternary C2 hydrocarbon mixtures remains an important and challenging goal for petrochemical industry. Current physisorbents either suffer from unsatisfied separation performance, poor stability, or are difficult to scale up. Herein, we report a strategy of constructing multiple supramolecular binding sites in a robust and scalable MOF (Al-PyDC) for highly efficient one-step C2H4 purification from ternary mixtures. Owing to suitable pore confinement with multiple supramolecular binding sites, Al-PyDC exhibits one of the highest C2H2 and C2H6 uptakes and selectivities over C2H4 at ambient conditions. The gas binding sites have been visualized by single-crystal X-ray diffraction studies, unveiling that the low-polarity pore surfaces with abundant electronegative N/O sites provide stronger multiple supramolecular interactions with C2H2 and C2H6 over C2H4. Breakthrough experiments showed that polymer-grade C2H4 can be separated from ternary mixtures with a maximum productivity of 1.61 mmol g−1. This material can be prepared from two simple reagents using a green synthesis method with water as the sole solvent, and its synthesis can be easily scaled to multikilogram batches. Al-PyDC achieves an effective combination of benchmark separation performance, high stability/recyclability, green synthesis and easy scalability to address major challenges for industrial one-step C2H4 purification. One-step separation of C2H4 from ternary C2 hydrocarbon mixtures remains a challenge for current physisorbents. Here, the authors reported a strategy of designing multiple supramolecular binding sites in a robust and scalable MOF for highly efficient one-step C2H4 purification from ternary mixtures. [ABSTRACT FROM AUTHOR]

LGa(P2OC)cAAC 2 features a 1,2‐diphospha‐1,3‐butadiene unit with a delocalized π‐type HOMO and a π*‐type LUMO according to DFT calculations. [LGa(P2OC)cAAC][K(DB‐18‐c‐6)] 3[K(DB‐18‐c‐6] containing the 1,2‐diphospha‐1,3‐butadiene radical anion 3⋅− was isolated from the reaction of 2 with KC8 and dibenzo‐18‐crown‐6. 3 reacted with [Fc][B(C6F5)4] (Fc=ferrocenium) to 2 and with TEMPO to [L−HGa(P2OC)cAAC][K(DB‐18‐c‐6)] 4[K(DB‐18‐c‐6] containing the 1,2‐diphospha‐1,3‐butadiene anion 4−. The solid state structures of 2, 3K(DB‐18‐c‐6], and 4[K(DB‐18‐c‐6] were determined by single crystal X‐ray diffraction (sc‐XRD). [ABSTRACT FROM AUTHOR]

Monovalent group 13 diyls are promising reagents for C−X bond activation. We here report on C−Br bond activation reactions of gallanediyl LGa (L=HC[C(Me)NAr)]2, Ar=2,6‐i‐Pr2C6H3)) with a variety of bromoalkanes. Reactions with alkylbromides R−Br gave the corresponding LGa(Br)R (R=Et 1, n‐Pr 2, i‐Pr 3), while the reaction with dibromomethane in 2 : 1 molar ratio occurred with geminal C−Br bond addition and formation of [LGa(Br)]2CH2 (4). In contrast, equimolar reaction of LGa with CHBr3 yielded LGa(Br)CHBr2 (5), which reacted with another equiv. of LGa with decomposition and formation of LGaBr2. Compounds 1–5 were characterized by heteronuclear (1H, 13C) NMR and IR spectroscopy, as well as single‐crystal X‐ray diffraction (sc‐XRD). [ABSTRACT FROM AUTHOR]

Developing porous materials to overcome the trade‐off between adsorption capacity and selectivity for C2H2/CO2 separation remains a challenge. Herein, we report a stable HKUST‐1‐like MOF (ZJU‐50a), featuring large cages decorated with high density of supramolecular binding sites to achieve both high C2H2 storage and selectivity. ZJU‐50a exhibits one of the highest C2H2 storage capacity (192 cm3 g−1) and concurrently high C2H2/CO2 selectivity (12) at 298 K and 1 bar. Single‐crystal X‐ray diffraction studies on gas‐loaded ZJU‐50a crystal unveil that the incorporated supramolecular binding sites can selectively take up C2H2 molecule but not CO2 to result in both high C2H2 storage and selectivity. Breakthrough experiments validated its separation performance for C2H2/CO2 mixtures, providing a high C2H2 recovery capacity of 84.2 L kg−1 with 99.5 % purity. This study suggests a novel strategy of engineering supramolecular binding sites into MOFs to overcome the trade‐off for this separation. [ABSTRACT FROM AUTHOR]

Vanadium dioxide (VO2) has attracted extensive attention due to the specific metal-insulator phase transition as well as the wide device applications. The practical performance of VO2-based device strongly depends on the quality of VO2, since the higher quality of VO2 film always shows much more pronounced phase transition behavior. Thus, the preparation of high quality VO2 film is essential and highly desirable. In this work, we have prepared high-quality VO2 film on SiC substrate by water vapor oxidation with graphene (G) buffer layer, which showed excellent phase transformation properties. Compared with the VO2/SiC sample without G buffer layer, the VO2/G/SiC films show the resistance changes up to four-orders of magnitude across the phase transition boundary and superior optoelectronic properties, which indicates the significant role of G layer in the film growth process. The current study not only provides an economical and feasible method for VO2/G/SiC thin film preparation with high quality, but also supply some clues for the application of G-based VO2 devices in the future.

The equation of state (EOS) of HfC and nanosized TiC at high pressure has been studied by means of synchrotron radiation X-ray diffraction (XRD) in a diamond anvil cell (DAC) at ambient temperature, and density functional theory (DFT) calculations. XRD analysis showed that the cubic structure of HfC and nanosized TiC maintained to the maximum pressures. The XRD data yield a bulk modulus K 0 = 2 8 6. 2 (4. 8) GPa with K 0 ′ = 3. 6 5 (0. 3 1) of HfC. In addition, the bulk modulus of nanosized TiC derived from XRD data is K 0 = 2 8 2. 9 (2. 1) GPa with K 0 ′ = 3. 9 5 (0. 1 4). [ABSTRACT FROM AUTHOR]

Abstract In order to improve cyclic stability and rate capability of Mn 2 O 3 as lithium-storage anode for lithium ion batteries, we propose a novel configuration: porous Mn 2 O 3 nanocubes encapsulated in carbon shell (Mn 2 O 3 @C). The porous structure provides space to buffer the volume change, while the surface carbon coating shell suppresses the electrolyte decomposition on Mn 2 O 3 and enhances the electronic conductivity of the anode. This unique configuration and its improved electrochemical performances are demonstrated by detailed physical characterizations and electrochemical measurements. It is found that the resulting Mn 2 O 3 @C retains a high reversible and stable lithium-storage capacity of 996 mAh g−1 at 0.2C (1C = 1018 mA g−1) after 200 cycles, while only 269 mAh g−1 for the porous Mn 2 O 3 nanocubes without surface carbon shell, and the Mn 2 O 3 @C possesses an excellent rate capability (299 mA h g−1 at 10C). This configuration provides not only Mn 2 O 3 but also other metal oxides with great potential application in high energy density batteries. Graphical abstract Image 1 Highlights • Porous Mn 2 O 3 nanocubes encapsulated in carbon shell are synthesized with leaving an internal void space. • Surface carbon coating shell suppresses the electrolyte decomposition on Mn 2 O 3. • The merits of carbon shell and void space are favorable for LIBs application. • Resulting product exhibits excellent performance as anode of lithium ion battery. [ABSTRACT FROM AUTHOR]

Abstract Novel single-phased white-emitting Ca 3 Y(GaO) 3 (BO 3) 4 :Ce3+,Tb3+,Sm3+ phosphors with high-efficiency, were successfully synthesized via traditional high temperature solid-state reaction method. X-ray diffraction, luminescence spectroscopy, fluorescence decay time and fluorescent thermal stability tests have been used to characterize the as-prepared samples. The energy transfer among of Ce3+, Tb3+ and Sm3+ ions in Ca 3 Y(GaO) 3 (BO 3) 4 host have been studied in detail. The mechanisms of Ce3+ → Tb3+ and Ce3+ → Sm3+ energy transfer were demonstrated to be dipole-dipole interactions. The emission color of the obtained phosphors can be easily tuned by controlling the doping concentration ratios of Ce3+/Tb3+/Sm3+. Particularly, under the excitation at 340 nm, Ca 3 Y(GaO) 3 (BO 3) 4 :0.01Ce3+,0.15Tb3+,0.01Sm3+ phosphor showed bright a white light with CIE coordinates of (0.2892, 0.2943) and internal quantum efficiency as high as 49.5%. By integrating this single-composition white-emitting Ca 3 Y(GaO) 3 (BO 3) 4 :0.01Ce3+,0.15Tb3+,0.01Sm3+ phosphor with a 365 nm near-ultraviolet (NUV) light emitting diode (LED) chip, we successfully fabricated a prototype white LED (WLED) device, which exhibited high-brightness nearly ideal white light with CIE coordinates of (0.310, 0.330), color rendering index of 72.7 and a correlated color temperature of 6624 K. These results demonstrate that the proposed single-composition white-emitting Ca 3 Y(GaO) 3 (BO 3) 4 :Ce3+,Tb3+,Sm3+ phosphors can serve as promising phosphors for the application of NUV-excited WLEDs. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Abstract An effective Ni/CeO 2 catalyst prepared by the polyol reduction method for degrading phenol into CH 4 , H 2 and CO 2 in supercritical water (SCW) was developed. About 80% carbon gasification efficiency can be achieved at 525 °C and 60 min with 5 wt% phenol, 0.098 kg/m3 water density and 0.5 g Ni/CeO 2 /g phenol catalyst, forming CH 4 and H 2 as the main gaseous products. Comparison study indicated that the efficiency of present Ni/CeO 2 catalyst was about 20% higher than that of a commercial catalyst, i.e., Ni/SiO 2 Al 2 O 3 from Sigma-Aldrich with 65 wt%Ni, at a reaction conditions of 500 °C and 30 min. The characterization analyses of BET, TPR, XRD, XPS and TEM indicated that there was a NiCe alloy formed in Ni/CeO 2 , which could be important to enhance the activities of the carbon gasification efficiencies and gas yields. A kinetic modelings were conducted and the results showed that the lnA and the activation energy (Ea) of gasification were 7.1 ± 0.5 and 58.1 ± 3.2 kJ/mol for the gaseous product, and were 2.6 ± 0.9 and Ea is 36.6 ± 5.6 kJ/mol for the char formation, respectively. The present Ni-based-metal Ni/CeO 2 catalyst is cheaper and has a potential application for the gasification to convert phenol into gases fuels in SCW process. Highlights • Ni/CeO 2 catalyst prepared by the polyol reduction method with the presence of alloys. • Ni/CeO 2 catalyst firstly applied for phenol gasification in SCW and performed well. • CH 4 is the major selected gas product from phenol gasification using Ni/CeO 2 in SCW. • The efficiency of Ni/CeO 2 was about 20% higher than that of the commercial catalyst. [ABSTRACT FROM AUTHOR]

ABSTRACT: The microstructures of poly(vinylidene fluoride) (PVDF)/soy protein isolate (SPI) films were successfully modulated via denatured SPIs. While vegetable proteins have been extensively researched as functional biomaterials in fabrication of polymer blends, the diverse polymer‐protein interactions because of complex protein structures have not received sufficient attention. In this study, the PVDF‐SPI interactions were tuned by different denaturation treatments including heat, sonication, and chemical denaturation by 2‐mercaptoethanol and sodium dodecyl sulfate, respectively. Phase morphologies, crystal structures of PVDF, and secondary structures of SPI were analyzed by scanning electron microscope, fluorescence imaging, X‐ray diffraction, and Fourier transformed infrared spectroscopy. While 90 °C denaturation and sodium dodecyl sulfate led to nonporous structures, all other denatured SPIs produced distinctive porous structures. The crystallinity of PVDF was reduced to different degrees, depending on the denaturation of SPI. The distinctive microstructures of PVDF/SPI films indicated the diversity of PVDF‐SPI interactions and its importance in functional polymer/protein blends. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 134, 46706 [ABSTRACT FROM AUTHOR]

ABSTRACT: The significance of aggregated protein structures in tuning structures and dielectric polarization of poly(ethylene oxide) (PEO)/soy protein isolate (SPI) films was studied. The aggregated protein structures, subjected to denaturation processes, are expected to alter polymer–protein interactions, leading to diverse material structures, and properties. However, this is still insufficiently understood. In this study, SPI was modified via different denaturation processes including heat, sonication, and pH‐control. According to structural analysis with scanning electron microscope, fluorescence imaging, X‐ray diffraction, and Fourier transformed infrared spectroscopy, both denaturation conditions and SPI content affected PEO–SPI interactions, producing distinctive microstructures of PEO and SPI phases, which subsequently caused different dielectric properties in ferroelectric analysis. Particularly, sonication treated‐SPI distinguished itself by generating a unique parabolic‐like composition dependence of dielectric polarization, in contrast to other modified SPIs. Polymer/protein blends have shown great potential in biomedical and electronic applications, which will be further benefited by the findings in this study. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46561. [ABSTRACT FROM AUTHOR]

Novel red-emitting phosphors of Ca3Y(AlO)3(BO3)4 doped with different concentrations of Mn4+ were successfully synthesized by a high-temperature solid-state reaction method. Crystal composition, microstructure, and luminescence properties of samples were characterized by X-ray diffraction, scanning electron microscope, excitation and emission spectra, decay lifetimes and temperature-dependent photoluminescence spectra. The emission spectra exhibited a strong deep-red emission band in the wavelength range of 625-750 nm with a maximum at 678 nm. The optimal doping concentration of Mn4+ was about 0.1 mol%. Under 325 nm excitation, the CIE chromaticity coordinates of Ca3Y(AlO)3(BO3)4:0.1%Mn4+ sample were (0.704, 0.296). In addition, the concentration quenching mechanism was dominated by a dipole-dipole interaction for the Mn4+ activators. The value of the activation energy Ea was calculated to explain thermal quenching. [ABSTRACT FROM AUTHOR]

The glass and glass ceramics containing SiO2-CaO-Fe2O3-P2O5 were prepared by sol-gel method. The influence of the Fe contents on the crystallization and local structure of the glass and glass ceramics was systematically investigated. The crystal structure of the glass ceramics was identified by XRD characterization. Hematite phase can be precipitated from the glass matrix in all glass ceramics with various Fe contents, and the crystallographic parameters of hematite were determined by XRD Rietveld refinement. The crystallization kinetics of the glasses was investigated in detail. Relative low activation energies were obtained at low Fe contents. The local structure evolution of the glass and glass ceramics has been studied in-depth by means of FTIR and Mössbauer spectroscopy. Fe element is present both as network former and network modifier which significantly influenced the crystallization activation energies of the glasses. The results of this work may be of great significance for the material design and practical applications of bioactive magnetic glass ceramics for hyperthermia. [ABSTRACT FROM AUTHOR]

Bi2MoO6 nanosheets with the different lanthanum contents were prepared by the facile hydrothermal method. The samples were characterized by X-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area, UV-Visible diffuse reflectance spectroscopy, and photoluminescence emission spectra. Results indicated that Bi2MoO6 nanosheets selectively exposed (0 0 1) facets as the main external surfaces with the manifold of La content. When the molar ratio of La:Bi is 0.5%, the obtained Bi2MoO6 sample exhibited the highest catalytic performance for RhB degradation under the visible light, which can be attributed to the synergic effect of optimum bandgap and the effectively separation of photogenerated electron-hole. The possible photolytic degradation mechanism was further discussed and the photogenerated holes (h+) was found to be the major active species. [ABSTRACT FROM AUTHOR]

The authors report a novel scheme for a grazing‐incidence spectrometer forming an excellent meridional flat field in its detector domain to deliver the desired spectral resolution throughout the full designated spectral range, while reducing the sagittal astigmatism substantially to enhance the spectral intensity. The optical properties of the system are thoroughly investigated and optimized, and the detector plane is fitted well to the meridional or sagittal focal curves. The authors demonstrated that a resolving power of 6000–18000 could be achieved within the `water window' (2–5 nm) for an effective meridional source size of 200 µm (r.m.s.), and it would be further improved to 20000–40000 if the source size was confined to 50 µm (r.m.s.). [ABSTRACT FROM AUTHOR]

Continuous silicon nitride (Si 3 N 4 ) fibers are considered as one of the most promising high-temperature wave-transparent fibers, the high-temperature performance of which need to be investigated. The Si 3 N 4 fibers were heat-treated at elevated temperatures for different duration times in air and N 2 atmosphere, respectively. The compositions, microstructures and mechanical properties were investigated by XRD, XPS, SEM and tensile strength analysis. The results show that the heat-treatment temperature, exposure time and atmosphere all have effects on the performance of the fibers. And the decrease in strength of the Si 3 N 4 fibers annealed in N 2 is due to the thermal decomposition of Si x N y O and grain growth of Si 3 N 4 , while the degradation of the fibers annealed in air is mainly owing to the oxidation reactions. [ABSTRACT FROM AUTHOR]

A novel 2D metal-organic framework, [(Cd 2 (PDIA) 2 ·3DMF]·3DMF (namely CdPDIA), was successfully constructed by an organic ligand 5-(phenyldiazenyl)isophthalic acid (H 2 PDIA) and Cd(II) ion. The resultant sample possesses binuclear {Cd 2 (COO) 4 } clusters and two different modes of the deprotonated organic ligand. Topologically, {Cd 2 (COO) 4 } clusters and PDIA 2 − ligands can be considered as 4-connected nodes and 2-connected linkers. Hence, the 2D structure can be further symbolized as a sql topology with the Schläfli symbol of (4 4 •6 2 ). The resultant sample CdPDIA has been characterized and analysed by single crystal diffraction, elemental analysis, powder X-ray diffractions and thermogravimetric analysis in detail. Due to metal sites in the framework of CdPDIA, it can be applied as a heterogeneous catalysis for the solvent-free conversion of CO 2 and epoxides into cyclic carbonate. In addition, the resultant sample can be recycled four times without significant activity decrease. [ABSTRACT FROM AUTHOR]

Investigations of equation of state, strength and texture of tungsten (W) have been performed under nonhydrostatic compression up to 96 GPa using an angle-dispersive radial X-ray diffraction (RXRD) techniques together with the lattice strain theory in a 2-fold paranomic diamond anvil cell (DAC) at ambient temperature. The ratio of t / G is found to remain constant above ∼35 GPa, indicating that the W started to experience macro yield with plastic deformation at this pressure. Combined with independent constraints on the high-pressure shear modulus, we found that W sample could support a differential stress of ∼4.57 GPa when it started to yield with plastic deformation at ∼35 GPa under uniaxial compression. The differential stress in W ranges from 0.01 GPa to 1.46 GPa with pressure increasing from 6 GPa to 35 GPa and can be described as t = −0.904(136) + 0.154(6) P , where P is the pressure in GPa. A maximum differential stress, as high as ∼6.46 GPa can be supported by W at the highest pressure of ∼96 GPa. In addition, we have investigated the texture of W under nonhydrostatic compression up to the highest pressure of 96 GPa using the software package MAUD (Material Analysis Using Diffraction). It is convinced that the plastic deformation due to stress under high pressures is responsible for the development of texture. [ABSTRACT FROM AUTHOR]

La/WO system were successfully built via a simply crystallization precipitation method using sodium tungstate and lanthanum nitrate hexahydrate as precursor. Samples were characterized by powder X-ray diffraction, UV-Vis absorbance spectroscopy, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and N adsorption-desorption isotherms (BET). Results showed that La does not enter into the crystal lattice of WO but located in the interstitial site and accordingly presented as the form of La-O-W in the interstitial site. In addition, doping of La restrict the grain size and the minimum crystal size was 28 nm at La:W = 3:10. Photocatalytic degradation of Rhodamine B showed that the modified samples had better catalytic performance. When La:W reaches 0.3, the La/WO nano-materials exhibits the highest photocatalytic activity, which can be attributed to the synergic effect of the higher BET surface area, surface hydroxyl content and optimum La contents. A possible mechanism for the photocatalytic degradation of RhB has also been provided. [ABSTRACT FROM AUTHOR]

FeO-CaO-SiO glass ceramics containing nucleation agent PO/TiO were prepared by sol-gel method. The samples were characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The activation energy and kinetic parameters for crystallization of the samples were calculated by the Johnson-Mehi-Avrami (JMA) model and Augis-Bennett method according to the results of DSC. The results showed that the crystallization mechanism of FeO-CaO-SiO glass, whose non-isothermal kinetic parameter n = 2.3, was consistent with surface crystallization of the JMA model. The kinetics model function of FeO-CaO-SiO glass, f(α) = 2.3(1-α)[-ln(1-α)], was also obtained. The addition of nucleation agent PO/TiO could reduce the activation energy, which made the crystal growth modes change from onedimensional to three-dimensional. [ABSTRACT FROM AUTHOR]

An experimental apparatus was designed to investigate the aluminothermic reduction of the mixture of MgO and Ca(OH) at normal atmosphere, 1223 K (950 °C), with the molar ratio of MgO:Al:Ca(OH) to be 3:2:1, reinforced by high-energy ball milling. The effect of mechanical milling time and content of grinding aid (sodium stearate) on the reduction ratio of MgO were studied. Moreover, the reduzate and reactant activated by ball milling were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectrometer analysis. The average grain sizes of Al and MgO activated by ball milling were also calculated by Scherrer formula. The results indicate that the reduction ratio of MgO is increased with increasing mechanical milling time and content of sodium stearate. The high-energy ball milling has good reinforcement on the aluminothermic reduction of MgO. Moreover, the strengthening mechanism of mechanical force on the reaction was further discussed. [ABSTRACT FROM AUTHOR]

Abstract: A nanocomposite of polyaniline (PANI)/mesoporous tungsten trioxide (m‐WO3) was synthesized by the chemical oxidation polymerization of aniline coated onto an ordered m‐WO3 and investigated as an anode material for lithium‐ion batteries. The nanocomposite was characterized by using X‐ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of the nanocomposite were evaluated by cyclic voltammetry and constant current charge/discharge tests. The reversible capacity of the PANI/m‐WO3 in the first cycle was 1064 mAh g−1 at 60 mA g−1 and remained at 803 mAh g−1 at 180 mA g−1 after 100 cycles, while the initial charge capacity of m‐WO3 was 556 mAh g−1 and remained only at 303 mAh g−1 after 50 cycles. The improved electrochemical performance of the nanocomposite can be ascribed to the electronical conductivity of PANI and the chemical interaction between PANI and m‐WO3. More importantly, the unique PANI coating layer on the m‐WO3 is believed to play an important role in the capacity contribution of the composite. [ABSTRACT FROM AUTHOR]

A series of TiO2 nanosheets are prepared with different amounts of AgNO3 and HF solution through a solvothermal process. The samples are characterized by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), laser Raman spectroscopy (LRS), electron paramagnetic resonance (EPR), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). From the results it is clear that the added HF solution inhibits the crystallite size growth in the [001] direction, and induces the formation of the TiO2 nanosheets with highly exposed (001) facets. There is a strong interaction between the Ag nanoparticles and the TiO2 support. The (Ag,F)-modified TiO2 catalyst exhibits high activity of MB photodegradation under both UV light and visible light irradiation. Two mechanisms of photocatalysis under UV light and visible light irradiation were discussed and proposed. It is indicated that the strong interaction between the Ag nanoparticles and the TiO2 support improves the photocatalytic activity of TiO2 nanosheets. [ABSTRACT FROM AUTHOR]

Five two-dimensional Hofmann-DMF-type compounds M(DMF)2 M′(CN)4 [ M = Cd, M′ = Ni ( 1), Pd ( 2), Pt ( 3); M = Fe, M′ = Ni ( 4), Pt ( 5)] were synthesized by solution diffusion method. X-ray diffraction analysis revealed that compounds 1- 5 are isomorphous and crystallize in the monoclinic C2/ m space group. The structure consists of corrugated cyanide-bridged polymeric networks, in which the DMF-ligated octahedral M and square-planar M′ atoms occupy special positions of the 2/ m site symmetry. In addition, the non-hydrogen atoms of DMF molecules locate on a crystallographic mirror plane and coordinate to the axial sites of M atoms from both sides of the sheets. Thermal stabilities of such system are associated with the metal ions involved in structures and the host framework begins to collapse with the loss of coordinated DMF molecules. [ABSTRACT FROM AUTHOR]

Highlights: [•] Four kinds of layered double hydroxides (LDHs) were synthesized to adsorb the DNA. [•] We compared the adsorption between different LDHs and discovered the difference. [•] Discussed the influence of various factors variables on adsorption process. [•] Some models were used to discuss the adsorption mechanism between LDHs and DNA. [Copyright &y& Elsevier]

A series of TiO2 hollow sphere catalysts with or without nonmetal (B,P) dopants and Ag-modification were prepared through a sol-gel process with styrene-methyl methacrylate copolymer (PSMMA) microspheres as the template. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), laser Raman spectroscopy (LRS), and UV/Vis diffuse reflectance spectroscopy (UV/Vis DRS), and their photocatalytic activities were evaluated by degradation of methylene blue (MB). Both B and P dopants could narrow the band gap of the TiO2 catalyst, and the loaded Ag only played the role of photoelectron transmitter. The two effects of the nonmetal dopants and the loaded Ag improved the photocatalytic activity of the TiO2 hollow spheres. Moreover, the hollow sphere structure and oxygen vacancies were beneficial to photocatalysis. Among all the catalysts prepared, Ag-modified (B,P)-codoped TiO2 hollow spheres exhibited the highest photocatalytic activity. [ABSTRACT FROM AUTHOR]

Abstract: A novel electrode, carbon felt-supported nano-molybdenum carbide (Mo2C)/carbon nanotubes (CNTs) composite, was developed as platinum-free anode of high performance microbial fuel cell (MFC). The Mo2C/CNTs composite was synthesized by using the microwave-assisted method with Mo(CO)6 as a single source precursor and characterized by using X-ray diffraction and transmission electron microscopy. The activity of the composite as anode electrocatalyst of MFC based on Escherichia coli (E. coli) was investigated with cyclic voltammetry, chronoamperometry, and cell discharge test. It is found that the carbon felt electrode with 16.7wt% Mo Mo2C/CNTs composite exhibits a comparable electrocatalytic activity to that with 20wt% platinum as anode electrocatalyst. The superior performance of the developed platinum-free electrode can be ascribed to the bifunctional electrocatalysis of Mo2C/CNTs for the conversion of organic substrates into electricity through bacteria. The composite facilitates the formation of biofilm, which is necessary for the electron transfer via c-type cytochrome and nanowires. On the other hand, the composite exhibits the electrocatalytic activity towards the oxidation of hydrogen, which is the common metabolite of E. coli. [Copyright &y& Elsevier]

Abstract: A TiO2 photocatalyst sensitized with commercial organic pigment Benzimidazolone Yellow H3G was conveniently prepared and characterized by FT-IR, UV–Vis, XRD, SEM and N2 adsorption–desorption isotherms. The adsorption capacities and photocatalytic activities of the new photocatalyst were evaluated by photocatalytic degradation of Methyl Orange, Rhodamine B and Acid Chrome Blue K under irradiation with visible light. The results indicated that the new photocatalyst extends the photoresponse of TiO2 from the UV to the visible region. The photocatalysed degradation rates of the three dyes were in the range of 89–95%. The influence of the pH of the solutions on the photocatalytic activity was investigated and the mechanism of action was also discussed. Photocatalytic activity of the catalyst is reproducible which demonstrates excellent stability and recyclability factors, which are crucial to industrial wastewater treatment. [Copyright &y& Elsevier]

Abstract: The electrolyte materials Ce0.9Gd0.1O1.9 (GDC) and La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM) were synthesized by means of glycine-nitrate processes, respectively, then GDC-LSGM composite electrolytes were prepared by mixing GDC and LSGM. The GDC and LSGM powders were mixed in the weight ratio of 95:5, 90:10 and 85:15 and named as GL9505, GL9010 and GL8515. Their structures and ionic conductivities were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and AC impedance spectroscopy. The grain sizes of GDC-LSGM composites could be increased distinctly and the grain boundary resistance could be significantly decreased by small addition of LSGM. The experimental results show that the GDC-LSGM composites exhibit excellent ionic conductivity and could significantly enhance the fuel cell performances. The open circuit voltages are higher in the cell with composite electrolytes than in the cell with single GDC as electrolyte at the working temperature. Among these electrolytes, GL9505 has the highest ionic conductivity and the maximum power density. [Copyright &y& Elsevier]

Abstract: Graphite and multi-walled carbon nanotubes (MWCNTs) irradiated by gamma-rays were studied by X-ray diffraction, Raman spectroscopy and transmission electron microscopy. The results show that gamma-irradiation improves the degree of structural order in graphite and an irradiation dose of 200kGy is the most effective. However, gamma-irradiation decreases the degree of graphitization of the nanotubes because of the generation of defects in the carbon atom lattice and produces an amorphous structure through knock-on displacements and sputtering of carbon atoms. When the irradiation dose exceeds 200kGy the defect dynamics change and the nanotubes are annealed. Curvature-induced strain, reduced dimensionality and a large surface area of the CNT are responsible for the difference between graphite and MWCNTs after gamma-irradiation. [Copyright &y& Elsevier]

Abstract: A benzene solution of Cp*Ir(CO)2 was irradiated for 10 h at room temperature, and then the reaction solution was exposed to air overnight, affording two cis–trans isomeric diiridium(Ir–Ir) complexes [Cp*Ir(μ-CO)(Ph)]2 (1 and 4), a mononuclear iridium complex Cp*Ir(CO)(Ph)2 (2), a diiridium(Ir–Ir) complex Cp*2(CO)2Ir2(μ 2-C6H4) (3), a novel hexanuclear iridium complex [Cp*2(μ 2-Ph)(μ 2-H)Ir2](μ 3-CO2)[Ir4(CO)11] (5), and trace biphenyl. The molecular structures of complexes 1–5 have been determined by single-crystal X-ray diffraction analysis. Moreover, we studied the reactivities and possible formation paths of some of these complexes. [Copyright &y& Elsevier]

Dinuclear iridium complexes [(C5Me4)(CH2)n(C5Me4)][Ir(COD)]2(2a: n= 2; 2b: n= 3; 2c: n= 4) are obtained fromthe reactions of the corresponding dilithiumsalts Li2[(C5Me4)(CH2)n(C5Me4)] (n= 2–4) with [Ir(μ-Cl)(COD)]2.Further oxidation of 2affords iodo-bridged polymericiridium complexes [(C5Me4)(CH2)n(C5Me4)(IrI2)2]m(3a: n= 2; 3b: n= 3; 3c: n= 4). Dinuclear iridium complexes [(C5Me4)(CH2)n(C5Me4)][IrI2(PPh3)]2(4a: n= 2; 4b: n= 3; 4c: n= 4) and [(C5Me4)(CH2)n(C5Me4)][IrI2(CO)]2(5b: n= 3; 5c: n= 4)are obtained from the reactions of 3with PPh3and CO, respectively. Dinuclear dicarbonyl iridium complexes [(C5Me4)(CH2)n(C5Me4)][Ir(CO)2]2(6b: n= 3; 6c: n= 4) are obtained from the reactions of 3with Zn and CO. Additionally, the cyclometalated dinucleariridium complexes 7b,c, 8b,c, 9b,c, and 10b,care obtained from the reactions of 3with thecorresponding nitrogen ligands in the presence of KOH. The molecularstructures of complexes 2a, 4a, 5b, 6c, and 7bhave been determined by single-crystalX-ray diffraction analysis. Moreover, we found that complexes 3and 4are efficient catalysts for the selectiveamine cross-coupling reaction. [ABSTRACT FROM AUTHOR]

The continuous downscaling of metal oxide semiconductor field effect transistors (MOSFET) on silicon, germanium, , etc. still demands the creation of new high-k dielectrics with even better material performance. In this research, a new ternary high-k dielectric film, , is deposited using electron-beam evaporation. The structure and high temperature interfacial thermal stabilities are investigated by X-ray diffraction (XRD), X-ray photon electronic spectra (XPS), infrared attenuated total reflection (ATR) and time of flight second ion mass spectroscopy (ToF-SIMS). The band gap and band offset are determined using the O 1s energy loss spectra and valence band difference between film and substrate, respectively, from the XPS spectra. Capacitance-voltage (CV) and current-voltage (IV) curves are measured to give an insight of the dielectric and leakage current of this material. It is found that crystallization temperature of is >1000°C. The high dielectric constant (k) = 24.6, large band gap (Eg) > 7 eV and low leakage current (1.8 × 10-4 A/cm2, 1 MV/cm) make to be a promising high-k candidate. [ABSTRACT FROM AUTHOR]

Three structurally diverse PbII coordination complexes, [Pb3O(OH)(4-sphth)]2(H2O) (1), [Pb(3,5-Hdhb)]H2O (2), and [Pb3(4-nphth)2(OH)2] (3) (4-H3sphth, 4-sulfophthalic acid; 3,5-H2dhb, 3,5-dihydroxybenzoic acid; 4-H2nphth, 4-nitrophthalic acid), were synthesized under hydrothermal conditions. X-ray diffraction analyses reveal that 1 is constructed from [Pb4O4] cubanes, based on which ladder-shaped structure is built via 4-H3sphth bridge. This is the first Pb4O4-containing polymer. The Pb2O2 units in 2 are bridged by two parallel 3,5-HDHB ligands along the a-axis and two other parallel 3,5-HDHB ligands along the b-axis, forming a 3-D framework. For 3, the crystal structure is built up of a layer motif consisting of corner-sharing pyramidal Pb3O units, which are linked through Pb corners to form a hexagonal unit. Each PbO6 polyhedron is connected to three polyhedra (Pb3O) via sharing an edge (two μ 3-oxygen atoms) and two faces (three μ 3-oxygen atoms), thus yielding an infinite 2-D Pb–O–Pb (3,6-net) honeycomb layer. The luminescence of 1–3 demonstrates that they may be good candidates for luminescent materials. [ABSTRACT FROM AUTHOR]

Two series of Cd1-xInxNNi3 (0 ≤ x ≤ 0.2) and Cd1-yCuyNNi3 (0 ≤ y ≤ 0.2) samples were prepared from CdO, In2O3, CuO, and nickel powders under NH3 atmosphere at 773 K. The structural and physical properties were investigated by means of X-ray powder diffraction temperature-dependent resistivity and magnetic measurements. X-ray powder diffraction results showed that the Cd1-xInxNNi3 and Cd1-yCuyNNi3 compounds have a typical antiperovskite structure, and the CdNNi3; Cd0.9In0.1NNi3, and Cd0.9Cu0.1NNi3 compounds show metallic temperature-dependent resistivity and exhibit a Fermi liquid behavior at low temperature. In contrast to the paramagnetism previously reported, the CdNNi3 sample exhibits very soft and weak ferromagnetism, and no superconductivity was found in the Cd1-xInxNNi3 and Cd1-yCuyNNi3 samples down to 2 K. Each sample exhibited very soft and weak ferromagnetism, and the temperature dependence of the magnetization of the Cd1-xInxNNi3 and Cd1-yCuyNNi3 samples can be well fitted to the combination of a Bloch term and a Curie-Weiss term. [ABSTRACT FROM AUTHOR]

Abstract: An ultrafine-grained (UFG) ZK60Mg alloy with an average grain size of ∼1.0μm was processed by extrusion at relatively low temperature (488K) with a high area reduction ratio (∼25). The mechanical behavior of the UFG Mg alloy is investigated over strain rates spanning nearly eight decades (10−4–104 s−1). The stress–strain responses in the quasi-static (∼10−4 s−1) and high rate (104 s−1) regimes exhibit the characteristic sigmoidal profile that is a signature of extension twinning. Further, this sigmoidal profile is accentuated at high rates, suggesting a rate effect of twinning induced hardening. X-ray diffraction (XRD) and analysis of the as-received and deformed microstructures indicate the occurrence of twinning even at the quasi-static rates of loading. This observation is contrary to some of the theoretical predictions that suggest suppression of twinning in Mg below critical grain sizes much larger than in the present work. From the XRD analysis we infer that the twin volume fraction increases with increasing applied strain rate. Transmission electron microscopy observations of the tested specimens reveal high density non-basal dislocations that may result from the activation of these slip systems following twinning-induced lattice reorientation. [Copyright &y& Elsevier]

A series of zinc(II) complexes (1–6) with the ligands 4′,5′-diaza-9′-(4,5-bis(methylthio)-1,3-dithiol-2-ylidene) fluorene (L1) or 4′,5′-diaza-9′-(4,5-bis(ethylthio)-1,3-dithiol-2-ylidene) fluorene (L2) have been prepared in the presence of different zinc(II) salts, [Zn(L1)2(NO3)(MeOH)](NO3)·CH2Cl2·0.5(MeOH)·0.5(EtOH) (1), [Zn(L1)2(PhCOO)]NO3·MeOH (2) (PhCOO = benzoic ion), [Zn(L1)2Cl] [Zn(L1)Cl2] [ZnCl3(MeOH)]·CH2Cl2·H2O (3), [Zn(L1)2(ClO4)2] (4), [Zn(L2)2Cl] [Zn(L2)Cl2] [ZnCl3(MeOH)]·0.5(MeOH) (5), and [Zn(L2)2(ClO4)2] (6). Five of the complexes (1–3, 5, and 6) have been structurally characterized by single-crystal X-ray diffraction. The preferred coordination geometry of the zinc(II) center is related to the coordinated anions. Complexes 1, 2and 6with oxo-anions display distorted octahedral geometry, while complexes 3and 5with chloride anions take five- and four-coordination geometries. The weak coordinated perchlorate anion prefers a transstructure, while the strong coordinated nitrate anion favors a cisstructure. The intermolecular CC, CS, and SS interactions lead to the assembly of the complexes into different supramolecular frameworks. The results of the 1H NMR, UV-vis, and fluorescent spectra display a large effect of metal coordination on the electron density of the ligand. Spectral data for the complexes is in agreement with the crystal structures. Finally, semi-empirical PM3 calculations were carried out to explain the relationship of the structures and the spectra. [ABSTRACT FROM AUTHOR]

Abstract: It is a compelling challenge to both improve ionic conductivity and mechanical properties in polymeric electrolytes, and to accomplish it through a simple processing method. This study reveals that poly(ethylene oxide)-block-polyethylene (PEO-b-PE) possesses a capability for enhancing the multiple performances of PEO-based polymer electrolyte, i.e., it functions as a multi-functional miscible filler for obtaining poly(ethylene oxide)(PEO)/lithium perchlorate (LiClO4) having such enhanced performances. In this paper, remarkable enhancements in both ionic conductivity and mechanical properties are presented and analyzed. Investigations on the ion transportation behavior in the polymer electrolytes through optical micrograph, X-ray diffraction, Fourier transform infrared, and dielectric spectrum analyses revealed that the ionic conductivity of a ternary polymer electrolyte, PEO/PEO-b-PE/LiClO4, was enhanced by an order of magnitude with the addition of this copolymer. The results of tensile tests showed the ultimate stress of the ternary polymer electrolyte increased to 7.29MPa, modulus 114.21MPa, and breaking strain 1142.53%, which are 2252%, 688% and 274% higher than that of PEO/LiClO4, respectively. This study highlights that this kind of copolymer is a promising candidate for high performance solid polymer electrolytes in lithium battery applications. [Copyright &y& Elsevier]

Abstract: The stearate anions intercalated Ni–Al hydrotalcite-like compounds were prepared by a coprecipitation method coupled with the microwave-hydrothermal treatment. Their structures were characterized using FT-IR, XRD, contact angle, SEM, TEM and thermal analysis. The XRD results indicate that the interlayer anions of the microwave radiation samples have better order and stronger electrostatic interactions with hydroxyl layers than those of the conventional aging 12h samples, the crystallinity of stearate anions intercalated Ni–Al hydrotalcite-like compounds can be rapidly enhanced in a short period of microwave treatment, and the stearate anions arrange in the form of a monolayer in the interlayer space for all samples. The morphology analysis results show that all samples consist of irregular and very thin platelets, while the crystals size of microwave treated samples was obviously smaller than that of the conventional aged samples. Based on the contact angle results, the surfaces of all samples show the hydrophobic property. This is due to the intercalation of stearate anions. The thermal analysis results point out that the sample obtained from microwave radiation 60min possesses the best thermal stability. The rapid synthesis method explored in this paper is a promising method for studying other anionic surfactant intercalated HTLc. [ABSTRACT FROM AUTHOR]

Abstract: Chitin powder was soaked in concentrated sodium hydroxide solution (45%, w/w), and freezed at −18/−35°C for further modification (the ratio of chitin and sodium hydroxide solution was 1:10, w/v). The degree of deacetylation (DDA) was determined by acid–base titration while the structural changes of the regenerated chitin after alkali-freezing treatment were investigated by X-ray diffraction (XRD), infrared spectroscopy (IR) and differential scanning calorimetry (DSC). The results showed that the formation and growth of ice crystal during the slowly freezing process could break the intra- and inter-molecular hydrogen bonds, disorganize the ordered molecular structure, destruct the compact crystal structure and decline the crystallinity. However, such structural damage was unstable and reversible. Nevertheless, the study explained that the alkali-freezing treatment was beneficial for further modification of chitin, which could significantly promote its solubility and accelerate the chemical reaction rate, while it could also keep its main molecular chains completely. [ABSTRACT FROM AUTHOR]

A novel fluorescent chemosensing hybrid material (Py-SBA-15) for detecting Hg2+ions in water was prepared through the functionalization of mesoporous silica (SBA-15) with a modified fluorescent chromophore, 1-(4′-hydroxyphenyl)-4-pyrenyl-2,3-diaza-1,3-butadiene (Py-OH). Py-OH covalently grafted to the coupling agent 3-(triethoxysilyl)propylisocyanate (TESPIC) was used as the precursor for the preparation of mesoporous hybrid material. The XRD data and TEM images of Py-SBA-15 confirm that the hexagonal ordered mesoporous structure is preserved after functionalization. Py-SBA-15 demonstrates a high selectivity for Hg2+ions in the presence of other metal ions, which results from a dramatic fluorescence enhancement by the addition of Hg2+ions upon the suspensions of Py-SBA-15. A good linearity (R2= 0.9989) between the fluorescence intensity of Py-SBA-15 and the concentration of Hg2+ions is constructed, and a satisfactory detection limit of 1.7 × 10−7g mL−1is obtained. More importantly, Py-SBA-15 shows good regenerative ability due to the greatly minimized leaching effect of the sensing molecules by covalent grafting strategy. These results presented in this paper indicate that this hybrid material could be a promising fluorescence chemosensor for detecting Hg2+ions. [ABSTRACT FROM AUTHOR]

A sedes of mono- and disubstiluted complexes, Fel2(CO)xL4-x = 2 or 3, is conveniently accessed from simple mixing of N-heterocyclic carbenes, phosphines, and aromatic amines with Fel2(CO)4, first reported by Hieber in 1928. The highly light sensitive complexes yield to crystallization and X-ray diffraction studies for six complexes showing them to be rudimentary structural models of the monoiron hydrogenase, [Fe]-H2ase or Hmd, active site in native (FeII(CO)2) or CO-inhibited (FeII(CO)3) states. Diatomic ligand (v(CO)) vibrational and Mössbauer spectroscopies are related to those reported for the Hmd active site. The importance of a serial approach for relating such parameters in model compounds to low spin FeII in the diverse ligation of enzyme active sites is stressed. [ABSTRACT FROM AUTHOR]

The new phase K12Au21Sn4 has been synthesized by direct reaction of the elements at elevated temperatures. Single crystal X.ray diffraclion established its orthorhombic structure, space group Pmmn (No. 59), a = 12.162(2); b = 18.058(4); Co 8.657(2) Å, V= 190) .3(7) Å3, and Z=2. The structure consists of infinite puckered sheets of vertex- sharing gold tetrahedra (Au20) that are tied together by thin layers of alternating four-bonded-Sn and -Au atoms (AuSn4). Remarkably, the dense but electron-poorer blocks of Au tetrahedra coexist with more open and saturated Au-Sn layers, which are fragments of a zinc blende type structure that maximize tetrahedral heteroatomic bonding outside of the network of gold tetrahedra, LMTO band structure calculations reveal metallic properties and a pseudogap at 256 valence electrons per formula unit, only three electrons fewer than in the title compound and at a point at which strong Au-Sn bonding is optimized. Additionally, the tight coordination of the Au framework atoms by K plays an important bonding role: each Au tetrahedra has 10K neighbors and each K atom has 8-12 Au contacts. The appreciably different role ot the p element Sn in this structure from that in the triel members in K3Au5In and Rb2Au3Tl appears 10 arise from its higher electron count which leads to better p-bonding (valence electron concentrations= 1.32 versus 1.22). [ABSTRACT FROM AUTHOR]

Abstract: Cerium fluoride (CeF3) thin films were evaporated to the germanium substrates at different substrate temperature from 100°C to 250°C. Structural and optical properties were characterized by X-ray diffraction (XRD), scan electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The morphology of samples deposited at different temperature can be closely related to preferred orientation. The infrared optical constants were obtained by fitting the transmission spectrum using Lorentz oscillator model. A simple example for fabrication of long-wave infrared broadband antireflection coating was also presented. [Copyright &y& Elsevier]

Abstract: TiN, TiC and Ti(C, N) films have been respectively prepared using closed-field unbalanced magnetron sputtering ion plating technology, with graphite target serving as the C supplier in an Ar–N2 mixture gas. Bonding states and microstructure of the films are characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) in combination with transmission electron microscopy (TEM). The friction coefficients are measured by pin-on-disc test and the wear traces of deposited films are observed by optical microscope. Results show that the TiN film and Ti(C, N) film exhibit dense columnar structure while the TiC film exhibits a mixed microstructure of main nanocrystallite and little amorphous phases. The Ti(C, N) film has the highest microhardness value and the TiC film has the lowest. Because of small amount of pure carbon with sp2 bonds existing in the film, the friction coefficients of Ti(C, N) and TiC multilayer films are lower than that of TiN film. In addition, the multilayer structure of films also contributes visually to decrease of friction coefficients. The TiC film has extremely low friction coefficient while the wear ratio is the highest in all of the films. The results also show that the Ti(C, N) film has excellent anti-abrasion property. [Copyright &y& Elsevier]

The alkali-metal gold trielides K3Au5Tr (Tr = In (I), Tl (II)) and Rb2Au3Tl (III) have been obtained directly from the elements, and their orthorhombic structures determined by single-crystal X-ray diffraction means (I/II: Imma, a = 5.562(1), 5.595(1); b = 19.645(4),19.706(4); c = 8.502(2), 8.430(2) Å; Z = 4, respectively; III: Pmma, a = 5.660(1), b = 6.741(1), c = 9.045(2) Å, Z = 4). These exhibit zigzag chains of Tr that link puckered sheets (I/II) or chains (III) of gold tetrahedra condensed through shared vertices. The segregation of Au and Tr components is striking relative to the evidently stronger and preferred Au−Tr bonding in neighboring gold- and alkali-metal-poorer triel phases. The close packing of K/Rb (A) about the gold tetrahedra gives each A and Au4 component 7−10 and 10 neighbors of the other type, respectively. Tight-binding−linear-muffin-tin-orbital−atomic sphere approximation band structure calculations show that the title phases lie near or at electronic pseudogaps. The gold substructure is the dominant feature of the densities of states, with moderately broad 5d10 features as favored by relativistic effects. Likewise, crystal orbital Hamilton population results indicate optimization of Au−Au bonding at the expense of the stronger heteroatomic Au−Tr interactions. Stabilization of these unusual structures appears to follow in part from the presence of numerous short and individually weak A−Au interactions, as manifested by appreciable mixing of s, p, and d valence orbitals on A into network bonding states, Au 5d in particular. These and related phases define a family of Au4-based phases with particularly low e/a values of 1.2∼2.3 (over all atoms, omitting Au 5d), closely related to the cubic Laves-type structures. The same region also contains Tr-richer tunnel and network structures with relatively fewer cations that also appear to be dominated by Au−Au and Au−Tr bonding. Gold tetrahedra share vertices and generate zigzag chains or puckered layers in these two novel structure types. The gold chain in Rb2Au3Tl shown is further interbridged by chains of the Tl atoms (olive green). [ABSTRACT FROM AUTHOR]

Abstract: Composites of Al2O3/ZrB2/ZrO2 ceramic were fabricated by technology of the hot-pressing sintering. The oxidation kinetics model of Al2O3/ZrB2/ZrO2 composite was established, and the high temperature oxidation behavior of the composite was studied. It was found that oxidation velocity increased as the ZrB2/ZrO2 content was raised at the same oxidation time. Oxidation test and XRD analysis indicated that the composites began to oxidate in 500–700°C. Meanwhile, the effect of oxidation on microstructure was analyzed. [Copyright &y& Elsevier]