Effect of Electron Beam Orientation on Exit Wave Function via Simulation of Electron Dynamic Diffraction

Based on the electron dynamic diffraction, phase shift of the exit wave function vs misorientation of the incident electron beam from the exact zone axis has been calculated for the [001] oriented copper. The result shows that the peak of phase shift is the maximum at the atom position as the electron beam along the exact [001] zone axis, and the peak value of phase shift decreases as increases of the misorientation. At small misorientation, i.e. less than 5 degree, change of the phase shift is minimal. The peak value of phase shift decreases significantly when the incident beam deviates form the zone axis over 10 degree and the exit wave has a planar configuration as the misoriention angle arrives -17 degree. The effect of this phase shift characteristics on the information extracted from the hologram has also been considered.     

运用X射线荧光光谱法对石榴石分类鉴定

本文介绍了运用X射线荧光光谱法对石榴石的化学组成元素进行剖析（定性及半定量分析），通过化学组分的不同来对石榴石进行分类、鉴定。     

Solvothermal synthesis of hexagonal ZnO nanorods and their photoluminescence properties

Pure hexagonal ZnO nanorods were synthesized by low-temperature (90 °C) solvothermal treatment of zinc acetate in 40-80 wt.% hydrazine hydrate aqueous solutions. The products were characterized by means of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electronic microscopy (TEM), selected area electron diffraction (SAED), and room temperature photoluminescence (RTPL) spectra. They show a strong UV emission at around 380 nm upon excitation at 360 nm using a Xe lamp at room temperature. The influence on the quality of the nanorods was investigated while the content of the solvent changed. The as-synthesized ZnO nanorods are promising materials for nanoscale optoelectronic devices due to their excellent UV emission properties.     

Synthesis of WO3 in nanoscale with the usage of sucrose ester microemulsion and CTAB micelle solution

WO₃ nanoparticles were successfully prepared using first the low temperature hydrolysis method and second the chemical reaction method in water-in-oil sucrose ester microemulsion consisting of S1570, 1-butanol, tetradecane and aqueous phase. In this study WO₃ nanoparticles also were prepared using the CTAB micelle solution. The resultant WO₃ nanoparticles have been investigated with X-ray diffraction (XRD), transmission electron microscopy (TEM), variable pressure scanning electron microscope (SEM) equipped with energy dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). The shape and particles size of the resultant WO₃ nanoparticles from both methods in sucrose ester microemulsion show similar spherical shape and size range between 10 and 50 nm. The WO₃ nanoparticles prepared with the CTAB micelle solution show spherical shape with the size range average of 25-50 nm.     

Phase relations and microwave dielectric properties of vanadium modified Ba5Nb4O15 ceramics

Microwave dielectric ceramics of Ba₅Nb_4−xV_xO₁₅ (x = 0-1) were prepared by a solid-state reaction method. Vanadium substitution can markedly lower the sintering temperature of Ba₅Nb₄O₁₅ from 1450 to 1100 °C. The X-ray powder diffraction analysis reveals the multiphase nature of this system. A hexagonal-to-orthorhombic phase transition was also observed for the BaNb₂O₆ secondary phase. The microwave dielectric properties, such as τ_f, ε_r and Q × f value, decreased with increasing vanadium content for samples sintered at 1100 °C. There was an apparent increase in τ_f and Q × f value for samples (x ≥ 0.5) sintered at 1200 °C due to the hexagonal-to-orthorhombic phase transition of the BaNb₂O₆ phase. These results suggested that the microwave dielectric properties of multiphase ceramics strongly depended on the phase compositions and the phase transitions.     

Combined kinetic and X-ray electron probe microanalysis characterization of local porosity variation and pore shape across anodic alumina films

Porous anodic alumina films on Al were prepared by anodic oxidation of Al in H₂SO₄ electrolyte at a constant temperature and current density and different thicknesses, up to ≈ 41 μm. Their cross section was examined by EPMA for revealing the variation of local porosity across the films and shape of pores while a kinetic model for film growth was developed describing the variation of pore diameter. It was found that the pores open, and local porosity increases, towards the film surface, predicting a conical pore shape, while the results coincided with those obtained by kinetic study. The EPMA analysis combined with kinetic results emerges as a promising tool for studying structural features of these films.     

Synthesis and in vitro bioactivity of a borate-based bioglass

A bioactive borate glass was synthesized through normal melting-derived route in this letter. The degradation and bioactivity of the glass were studied by the immersion of glass microspheres in a dilute K₂HPO₄ solution. The cell growth inhibition rate of the borate glass was examined by MTT assay. The conversion product of the borate glass was identified by XRD, SEM. It was confirmed that the borate glass had a rapid degradation rate, comparing with the silicate-based bioglass, 45S5 glass. HA formed from the borate glass, that is an indication of bioactive potential in vivo. MTT assay results demonstrate that the inhibition effect of B ions released from the borate glass on cell proliferation can be alleviated by diluting extract solution to a certain concentration (v/v ratio: 1:4, [B] < 1.792 mM). It is believed that the borate glass could be a desirable biomaterial for preparing scaffold of tissue engineering.     

Diamond like carbon coatings deposited by microwave plasma CVD: XPS and ellipsometric studies

Diamond-like carbon (DLC) films were deposited by microwave assisted chemical vapour deposition system using d.c. bias voltage ranging from −100 V to −300 V. These films were characterized by X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry techniques for estimating sp ³/sp ² ratio. The sp ³/sp ² ratio obtained by XPS is found to have an opposite trend to that obtained by spectroscopic ellipsometry. These results are explained using sub-plantation picture of DLC growth. Our results clearly indicate that the film is composed of two different layers, having entirely different properties in terms of void percentage and sp ³/sp ² ratio. The upper layer is relatively thinner as compared to the bottom layer.     

Study of the effect of process parameters for n-heptylamine plasma polymerization on final layer properties

Plasma polymerization processes are widely used to chemically functionalize surfaces, which properties can be tuned by different operating variables. In this study, thin amine-containing polymer layers were produced on solid substrates in a custom-made cylindrical plasma polymerization reactor by radio frequency glow discharges of n-heptylamine vapours. Carefully planned experiments were conducted to evaluate the importance of four different process parameters on the chemical composition and thickness of the resulting films. The parameters investigated were: 1) deposition time, 2) power of the glow discharge, 3) distance between the electrodes, and 4) monomer pressure. Possible interactions between these variables were investigated through the use of statistical analyses (i.e., factorial design). This study reveals that n-heptylamine plasma polymer (HApp) layer thickness is influenced by the power of the glow discharge and the deposition time, as assessed by surface plasmon resonance and atomic force microscopy step height measurements. Also, the atomic ratio of nitrogen to carbon atoms on the treated surfaces is mainly influenced by the power of the glow discharge, as revealed by X-ray photoelectron spectroscopy. Quartz crystal microbalance analysis also confirmed that HApp layers are stable when immersed in aqueous solution.     

Deposition of AlN films by reactive sputtering: Effect of radiofrequency substrate bias

Piezoelectric AlN thin films were deposited on Silicon substrates by triode reactive sputtering. The variation of residual stress versus bias voltage on the substrate was investigated. A compressive stress was always observed with a maximum value for a negative substrate bias of 50 V. For higher negative bias voltage values, the compressive stress decreases. X-ray diffraction measurements showed two kinds of growth orientation. First, without bias voltage, films are well crystallized and (002) oriented. Second, with bias voltage, the (002) orientation disappears and a small peak appears (situated in the 2θ = 32°-33° range) which can be attributed to (100) orientation. Finally, the influence of compressive stress and ion bombardment on the change of orientation is discussed.