X-ray Diffraction Spectrometer Research Articles

Fabrication and Magnetic Properties of Amorphous Co1-xPx Alloy Nanowire Arrays

Amorphous Co1-xPx alloy nanowire arrays with different sizes and 6.8 wt% x 9.9 wt% were fabricated in an anodic aluminum oxide film by electrodeposition. Transmission electron microscopy, selected area electron diffraction, X-ray fluorescence spectrometer, inductively coupled plasma-atomic emission spectrometer, X-ray diffraction spectrometer and vibrating sample magnetometer are employed to study the morphology, chemical composition, structure and magnetic properties of the nanowire arrays, respectively. The results show that the Co1-xPx alloy nanowire arrays with x 6.8 wt% are amorphous. Due to the shape anisotropy effect, the coercivity of nanowire arrays is large for the applied field along the nanowires axis, and nanowire arrays have obvious magnetic anisotropy. The amorphous Co-P alloy nanowire arrays are good candidates for ultra-high-density magnetic recording media.

An improved method for chemical bath deposition of ZnS thin films

ZnS thin films were prepared by an improved chemical bath deposition method, which the substrates were preheated before being mounted in the reaction solution. X-ray diffraction (XRD) and energy dispersive spectrometer (EDS) reveals that thin film ZnS has a cubic structure and the typical composition ratio of Zn/S is 52:48. Scanning electron microscopy (SEM) characterization shows that the surface of the sample is compact and uniform. The transmission spectrum indicates a good transmission characteristic with an average transmittance of 82.2% in the spectra range from 350 nm to 800 nm and the optical band gap is about 3.76 eV.

Electrochemistry of Manganese in the Hydrophilic N-Butyl-N-methylpyrrolidinium Dicyanamide Room-Temperature Ionic Liquid

The electrochemistry of manganese was studied at a polycrystalline platinum disk electrode in the hydrophilic ionic liquid -butyl--methylpyrrolidinium dicyanamide (BMP-DCA). The density and absolute viscosity of BMP-DCA were determined over a temperature range from 299.0 to 343.0 K. A polynomial equation describing the temperature dependence of the density is provided. The viscosity obeys the Arrhenius temperature dependence. The dicyanamide anion exhibits a good complexing ability toward transition metal ions, and, therefore, Mn(II) species can be introduced into the ionic liquid either by anodic dissolution of a manganese electrode or by dissolution of manganese (II) chloride. Cyclic voltammograms indicated that the electrodeposition of Mn from Mn(II) was preceded by an overpotential-driven nucleation process. When the potential scan was reversed, the anodic stripping wave was fairly smaller than the cathodic wave, indicating that the oxidation of the Mn electrodeposits was kinetically hindered. However, this behavior was less noticeable for massive Mn electrodeposits. Manganese coatings were prepared at copper substrates by controlled-potential electrodeposition and characterized by scanning electron microscope, energy-dispersive spectrometer (EDS), and powder X-ray diffraction spectrometer (XRD). EDS analysis indicated that the purity of the Mn electrodeposits was good, although no crystal signal of Mn was observed in the XRD patterns.

Surface ligand effects in MEH-PPV/TiO 2 hybrid solar cells

TiO 2 nanorods (NRs) were synthesized by hydrolysis of titanium tetraisopropoxide (TTIP) using oleic acid (99%) as surfactant at low temperatures (80–100 °C) and are modified with different ligands: oleic acid (OLA), n-octyl-phosphonic acid (OPA) and thiophenol (TP) in order to investigate the effect of surface ligand on the excition dissociation and the charge transport in hybrid MEH-PPV/TiO 2 photovoltaic (PV) cells. The morphology and crystalline form of as-prepared TiO 2 NRs are examined by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD) and Raman spectrometer (RS). The FTIR analysis confirms all the ligands coordinated with the Ti center of TiO 2 NRs. The optical properties of the modified TiO 2 NRs are characterized by UV–vis absorption spectra and photoluminescence (PL) spectra. Thiophenol modified TiO 2 NRs quench the PL of MEH-PPV more effectively than OLA-TiO 2 NRs and OPA-TiO 2 NRs. The power conversion efficiency of hybrid PV cells from thiophenol modified TiO 2 NRs and MEH-PPV is the highest among the investigated TiO 2 NRs.

The development of the physical and electrical characteristics of multi-layer TiO2–W–TiO2 thin films

In this study, two different thin films, TiO2 thin film and TiO2–W–TiO2 multi-layer thin films (W, tungsten), are prepared by RF magnetron sputtering onto glass substrates. The crystal structure, morphology, and transmittance of TiO2 and TiO2–W–TiO2 multi-layer thin films are investigated by X-ray diffraction, SEM, and UV-Vis spectrometer, respectively. The amorphous, rutile, and anatase TiO2 phases are observed in the TiO2 thin film and in the TiO2–W–TiO2 multi-layer thin films. The deposition of tungsten as the inter-layer will have large effect on the transmittance and phase ratios of rutile and anatase phases in the TiO2–W–TiO2 multi-layer thin films. The crystal intensities of amorous TiO2 will decrease as the tungsten is used as the middle layer in the multi-layer structure. The band gap energy values of TiO2 thin film and TiO2–W–TiO2 multi-layer thin films are evaluated from (αhν)1/2 versus energy plots, and the calculated results show that the energy gap decreases from 3.21 eV (TiO2 thin film) to 3.08∼3.03 EV (TiO2–W–TiO2 multi-layer thin films).

Chicken Eggshell as a Filler for Polymer Composites: Preparation and Characterizations

In this research, the eggshell was thermally treated at 700°C for 1-3 hrs and 800°C for 1- 4 hrs. After the treatment, thermally treated eggshell was characterized via X-ray diffraction spectrometer, particle size analyzer and thermogravimetric analyzer. From the XRD patterns, it revealed that calcium carbonate was obtained when chicken eggshell was treated at 700°C. The content of calcium carbonate, however, decreased with increasing heating times and temperature. After the eggshell was heated at 800°C, calcium hydroxide was mainly obtained and eventually when the treatment time was 4 hrs, instead of calcium carbonate, calcium hydroxide and calcium oxide were obtained. The size of the treated eggshell was about 0.06 – 878.7 µm depending on the treatment times and temperatures. The size distribution of 800°C-treated eggshell was narrower than that of the 700°C-treated eggshell.

Study of Nanometer Al<sub>2</sub>O<sub>3</sub> Composite Electroless Deposit Strengthened by Different Laser Power

Featured by cheap equipment, easy operation, nice controllability and low consumption, compound electroless deposit becomes an effective method to avoid failures such as high-temperature corrosion, fatigue and abrasion. Combined with the merits of nanometer material and laser treatment technology, the Ni-P nanometer Al2O3 electroless deposit after laser strengthening can get finer grains with high performances. This paper researched the technique of laser strengthening on 3Cr13 stainless steel after Ni-P-nano Al2O3 electroless plating. The experiments with low laser power and high laser power were performed. The crystallinity, phases and element distribution of coating were analyzed by X-ray Diffraction (XRD) and energy spectrometer (EDS). The microhardness and wear resistance of coating were measured as well. The results showed that composite coating heated by low laser power leads to transformation from non-crystal to crystal with high hardness. When heated by high laser power, the electroless deposit layer melted, and most of amorphous transformed to crystal. Combined with high laser power and high scanning velocity, the electroless deposit with finer grains and excellent properties was obtained. The strengthening mechanism was analyzed, and the properties including hardening and wear resistance were investigated as well.

Photocatalytic properties and optical absorption of ZnFe2O4 doped TiO2 films

TiO2 films doped with ZnFe2O4 were prepared by a sol–gel method. The crystalline structure, photocatalytic efficiency and optical absorption band were investigated using X-ray diffraction and Ultraviolet-Visible spectrometer. The doping of ZnFe2O4 improves the photocatalytic efficiency and broadens the optical absorption band of TiO2 films. The photocatalytic efficiency of TiO2 films increases from 12 to 32% with the presence of ZnFe2O4. The exciting wavelength of TiO2 films shifts about 20 nm to the visible light regions when the molar ratio of ZnFe2O4 is 2%.

Preparation of Rutile and Anatase Phases Titanium Oxide Film by RF Sputtering

Titanium oxide films were prepared by RF magnetron sputtering onto glass substrates. The effects of RF power and deposition temperature on crystalline structure, morphology and energy gap were investigated, which were analyzed by X-ray diffraction, SEM and UV-Vis spectrometer, respectively. Results show that rutile phase is the favored structure during deposition. Applying RF power in the range of 50-250 W, the amorphous, rutile, and both rutile and anatase phases TiO2 films were obtained in sequence, while the content of anatase is similar in the range of 34-37% although the RF power increases. Increasing the deposition temperature, the anatase phase coexists in the rutile phase in the range of 100-200 degrees C, and the content of anatase increases from 20 to 41% with the deposition temperature. In addition, according to the morphology observation, the granulous surface is found in rutile phase while facetted surface in anatase phase when titanium oxide films deposited at various RF powers and substrate temperatures. The band gap energy of titanium oxide evaluated from (alphahv)1/2 versus energy plots show that the energy gap decreases with RF power increasing.

Microstructure study of laser welding cast nickel-based superalloy K418

Experiments of laser welding cast nickel-based superalloy K418 were conducted. Microstructure of the welded seam was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectrometer (EDS). Mechanical properties of the welded seam were evaluated by microhardness. The corresponding mechanisms were discussed in detail. Results show that the laser welded seam have non-equilibrium solidified microstructures consisting of Cr–Ni–Fe–C austenite solid solution dendrites as the dominant and some fine and dispersed Ni 3(Al,Ti) γ′ phase as well as little amount of MC needle carbides and particles enriched in Nb, Ti and Mo distributed in the interdendritic regions, cracks originated from the liquation of the low melting points eutectics in the HAZ grain boundary are observed, the average microhardness of the welded seam and HAZ is higher than that of the base metal due to alloy elements’ redistribution of the strengthening phase γ′.

オクタデシルトリクロロシラン処理された石英ガラス基板上のポリ（３‐ヘキシルチオフェン）薄膜の形態と非線形光学特性

Polythiophene derivatives in π-conjugated polymers have been attracting the attention of researchers as derivatives retaining extensively potential applications in optoelectronics such as optical switches, optical logic circuits, optical integrated circuit (IC) and so forth. As π-conjugated polymers have high non-localized π electron density, the thin film prepared by π-conjugated polymers has the possibility of a large third order nonlinear optical susceptibility occurring from the thin film. In this study, the π-conjugated polymer used is regioregular poly (3-hexylthiophene-2, 5-diyl) {P3HT}. The substrate preparing P3HT thin film is quartz glass treated by octadecyltrichlorosilane (ODTS) or hexamethyldisilazane (HMDS). P3HT thin films are prepared by a drop-casting on it formed on the surface of quartz glass with self-assembling monolayer (SAM) [ODTS or HMDS]. The molecular orientation or alignment of P3HT thin films with and without SAM is performed using an X-ray Diffraction (XRD) spectrometer and UV/Vis spectrophotometer. Based on these results, the nonlinear optical characteristics of P3HT thin films with and without SAM are performed and investigated with the third harmonic intensity measured by the Maker fringe method.

Characterization of Chromite Ore Processing Residue

This paper summarizes the characteristics of chromite ore processing residue (COPR) in terms of their chemical compositions, phases, and recycling potential of iron and chromium through preliminary magnetic separation. COPR from nine hazardous waste sites in Hudson County, N.J., were analyzed using nondestructive instruments including environmental scanning electron microscope, x-ray diffraction spectrometer, and x-ray fluorescence spectrometer. The test results revealed that major phases of COPR were CaCO3, iron/chromium containing spinel, and SiO2. Concentrations of iron-containing phases, calculated as Fe2O3, ranged from 10 to 33% by weight. The COPR samples from nine sites can be divided into two groups, one with high concentration of iron oxide (20–33%) in a form of spinel having magnetic property, and another with low concentration of iron oxide (10–15%) without magnetic property. The manual/dry magnetic separation was able to concentrate iron and chromium oxides in COPR from the former group to 34.9–40.9 and 6.3–8.6%, respectively. The morphology of COPR from a sample containing high iron content revealed that COPR is mainly the remnant of chromite ore. The characteristics of COPR are different from those chromium-contaminated soils from other sources. The study will provide essential information for further remediation and recycling potential for COPR.

Characteristics of nano zinc oxide synthesized under ultrasonic condition

Hydrothermal method is employed to synthesize nano ZnO particles in solutions containing different surfactant at room temperature and 50 °C under ultrasonic condition. The reactants used are aqueous solutions of zinc chloride and potassium hydroxide, and the surfactants are cetyltrimethylammonium bromide (CTAB) and triethanolamine (TEA). Instruments including synchrotron-based X-ray absorption spectroscope (XAS), Brunauer–Emmett–Teller (BET) surface meter, X-ray diffraction (XRD) spectrometer, and transmission electron microscope (TEM) are used to characterize the properties of the reaction product. All synthesized ZnO samples are in the form of zincite. The particle size of the nano ZnO powders synthesized at room temperature is approximately 46–61 nm (i.e., corresponding to BET surface areas 17.5–23.0 m 2 g −1). ZnO particle size can be effectively reduced to approximately 28–39 nm (i.e., corresponding to BET surface areas 27.4–38.9 m 2 g −1) if the synthesis processes in the ultrasonic water bath are kept at 50 °C. Moreover, the ZnO powder dispersion is considerably improved when the synthesis is carried out at 50 °C. The intensities of white bands in the X-ray absorption near-edge structure (XANES) spectra from all nano ZnO samples are relatively smaller than that from bulk ZnO. The position (i.e., photon energy (eV)) of the white band peak in the XANES spectrum from the nano ZnO synthesized under CTAB surfactant at 50 °C dramatically shifts to a greater value by approximately +3.6 eV, as compared with those from all other nano ZnO samples, indicating unique electronic state of this sample.

Properties of Al heavy-doped ZnO thin films by RF magnetron sputtering

Al-doped ZnO films were deposited by RF magnetron sputtering. From the X-ray diffraction and scanning electron spectrometer studies, wurtzite structure with (0 0 2) orientation ZnO thin films were obtained at Al concentration below 15 atomic percent (at.%). As the Al concentration above 15 at.%, the thin films did not fully crystallize. Two new emission peaks occurred at 351 nm and 313 nm when the Al doping above 15 at.% from the photoluminescence spectrum, and the peaks shift towards the shorter wavelengths with increasing the Al concentration. X-ray photonic spectra of O 1s conformed the amount of oxygen captured by Al 3+ increasing as the Al 3+ concentration increasing due to the dominant Al 3+ possess high charge in competition with Zn 2+ in the matrix of ZnO.

Synthesis and Characterization of PbSe Nanocrystals by a Microchannel Reactor

The synthesis of high-quality monodispersed nanocrystal is very important. Typical synthetic method is rapid nucleation by injection of an organometallic precursor into a solvent maintaining the reaction temperature. Since these methods are discontinuous processes, they are not efficient for large-scale production of monodisperse nanocrystals. In this study, continuous microchannel reaction technique is presented for synthesis of monodisperse lead selenide nanocrystals in a diphenyl ether as high-temperature organic media. The microchannel reactor was used due to its possibility of continuous process and reproducibility of narrow size distribution in nanocrystal synthesis. The synthesis was carried out in microchannel reactor (800 μm diameter) made from PTFE. Lead oleate and TOP-Se were used as organic precursor and diphenyl ether as high-temperature organic solvents. Lead selenide particles with a size of less than 10nm could be continuously prepared by this method. The nanocrystals have been characterized by X-ray diffraction, TEM and optical absorption spectrometer.

Modelling diffractive X-ray scattering using the EGS Monte Carlo code

An extension to the EGSnrc Monte Carlo code has been developed that allows diffractive scattering to be modelled from both crystalline and amorphous materials. The extended code allows the user to specify cross-sections and form-factors for materials and implements the physics of scattering from powdered crystals and amorphous materials. A computer code has been developed to facilitate the calculation of the cross-sections and form-factors of materials containing mixtures of crystalline and amorphous components. A modified next-event point-flux tally estimator has also been developed as a variance reduction technique specifically for diffractive scattering from crystals. The extended EGSnrc code has been used to optimise the design of a prototype energy-dispersive X-ray diffraction spectrometer. Initial results show promising agreement between the energy spectrum of diffracted X-rays obtained using the Monte Carlo model and measured experimentally.

Dissimilar autogenous full penetration welding of superalloy K418 and 42CrMo steel by a high power CW Nd:YAG laser

Experiments of autogenous laser full penetration welding between dissimilar cast Ni-based superalloy K418 and alloy steel 42CrMo flat plates with 3.5 mm thickness were conducted using a 3 kW continuous wave (CW) Nd:YAG laser. The influences of laser welding velocity, flow rate of side-blow shielding gas, defocusing distance were investigated. Microstructure of the welded seam was characterized by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). Mechanical properties of the welded seam were evaluated by microhardness and tensile strength testing. Results show that high quality full penetration laser-welded joint can be obtained by optimizing the welding velocity, flow rate of shielding gas and defocusing distance. The laser-welded seam have non-equilibrium solidified microstructures consisting of γ-FeCr 0.29Ni 0.16C 0.06 austenite solid solution dendrites as the dominant and very small amount of super-fine dispersed Ni 3Al γ′ phase and Laves particles as well as MC needle-like carbides distributed in the interdendritic regions. Although the microhardness of the laser-welded seam was lower than that of the base metal, the strength of the joint was equal to that of the base metal and the fracture mechanism showed fine ductility.

Effects of La 2O 3 on microstructure and wear properties of laser clad γ/Cr 7C 3/TiC composite coatings on TiAl intermatallic alloy

The effects of La 2O 3 addition on the microstructure and wear properties of laser clad γ/Cr 7C 3/TiC composite coatings on γ-TiAl intermetallic alloy substrates with NiCr–Cr 3C 2 precursor mixed powders have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive spectrometer (EDS) and block-on-ring wear tests. The responding wear mechanisms are discussed in detail. The results are compared with that for composite coating without La 2O 3. The comparison indicates that no evident new crystallographic phases are formed except a rapidly solidified microstructure consisting of the primary hard Cr 7C 3 and TiC carbides and the γ/Cr 7C 3 eutectics distributed in the tough γ nickel solid solution matrix. Good finishing coatings can be achieved under a proper amount of La 2O 3-addition and a suitable laser processing parameters. The additions of rare-earth oxide La 2O 3 can refine and purify the microstructure of coatings, relatively decrease the volume fraction of primary blocky Cr 7C 3 to Cr 7C 3/γ eutectics, reduce the dilution of clad material from base alloy and increase the microhardness of the coatings. When the addition of La 2O 3 is approximately 4 wt.%, the laser clad composite coating possesses the highest hardness and toughness. The composite coating with 4 wt.%La 2O 3 addition can result the best enhancement of wear resistance of about 30%. However, too less or excessive addition amount of La 2O 3 have no better influence on wear resistance of the composite coating.

The Use of Bentonite to Remove Dark Colour in Repeatingly Used Palm Oil

Acid-activated bentonite was used as a bleaching agent to remove the dark color in repeatingly used palm oil. Two bentonite samples with different colors were used. It was found that the paler one gave better bleaching results. The optimum condition needed 5 h to reflux bentonite with sulfuric acid; pH of the bentonite suspension was 3, bleaching temperature was 80–85°C and bleaching time was 30 min. The experiments also showed that bentonite could adsorb impurities and toxic compounds such as benzo(a)pyrene in palm oil. Chemical and physical properties of the bentonite samples were analyzed by X-ray fluorescence spectrometer (XRF), X-ray diffraction spectrometer (XRD) and scanning electron microscope (SEM). Particle size and specific surface area were also studied.

The corrosion behavior of Fe 3Al in gas mixtures of oxygen and chlorine at 700 °C

The high-temperature corrosion of Fe 3Al in various O 2/Cl 2 mixtures has been investigated at 700 °C. The corrosion kinetics was obtained using thermogravimetric analysis and microstructural study was conducted for the corrosion products by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The thermogrvimetric results indicate that depending on oxygen/chlorine ratio, the corrosion exhibits various kinetic modes with different corrosion rates. The complex corrosion products were formed during the corrosion. A quasi-stability diagram was utilized to explain the corrosion of Fe 3Al in the gas mixtures.