X-ray Diffraction Spectrometer Research Articles

Hydrothermal synthesis of LiMn xCo 1− xO 2 cathode materials

Ultrafine powders of LiMn x Co 1− x O 2 ( x = 0.2–0.9) cathode materials for lithium-ion secondary batteries are successfully prepared under mild hydrothermal conditions from KMnO 4, MnCl 2 and Co(NO 3) 2·6H 2O. The influence of the molar ratio of Mn/Co and the reacting temperature are studied. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS) are used to characterize the obtained final particles. The final products are found to be well crystallized LiMn x Co 1− x O 2 as the molar ratio of Mn/Co is less than 5/5. Transmission electron microscopies (TEM) revealed that the powders are composed of nanosized crystallites with ununiform shape and average size of 10–50 nm. It has been found that the cystallinity of the LiMn x Co 1− x O 2 powders increased with the reacting temperature rise. And when Mn/Co = 4/6, the sample has good cation ordering.

The Comparison of Electrolysis Manganese Craft on Stainless Steel and Titanium

In this paper, Potentiodynamic scans and Potentiostatic experiments are used to study manganese electro deposition on stainless steel and titanium substrates from simple chloride solutions with addition of ammonium chloride. The surface morphology and the crystal structure of manganese electrodeposits are analyzed by scanning electron microscope (SEM) and powder X-ray diffraction spectrometer (XRD), respectively. The comparison of electrolysis manganese craft on stainless steel and titanium, It is found that precipitation hydrogen is easier and the cell voltage is higher on stainless steel ,but there are more side reactions on titanium; The cubic crystal form manganese deposite on stainless steel and titanium, but the higher pure degree manganese can be obtained on stainless steel, the depositions on the titanium are imply impurity.

Electrodeposition and corrosion behavior of Zn–Ni and Zn–Ni–Fe2O3 coatings

A thin film of Zn–Ni–Fe2O3 on steel substrates was prepared by electrodeposition technique using Zn–Ni alloy plating solution with nano-sized Fe2O3 particles. The cathodic polarization and cyclic voltammetry techniques were used to explain deposition process. The corrosion behavior of deposits was evaluated by polarization and impedance studies. Scanning electron microscope (SEM) images were used to study the surface morphology of coating. The grain size and amount of Fe2O3 particles present in composite coating were measured by X-ray diffraction pattern (XRD) and energy dispersive X-ray diffraction spectrometer (EDS), respectively.

Study of electroactive shape memory polyurethane–carbon nanotube hybrids

A low temperature electroactive shape-memory material, PU–SWCNT hybrid, was prepared by blending the low molecular weight soft segment polyurethane (PU) with the high conductivity single-walled carbon nanotubes (SWCNTs). The melting points of PU–SWCNT hybrids were changed clearly with the amount of SWCNTs, which were evidently observed by a differential scanning calorimeter (DSC). The influence of the SWCNT contents on the crystal structure of the PU–SWCNTs was detected by X-ray diffraction spectrometer and a hydrogen-bond reconstructed model was proposed in this study. The properties of the PU–SWCNT hybrids are characterized by thermogravimetric analysis (TGA), four-point probe and scanning electron microscopy (SEM). The extent of electroactive shape memory effect for the PU–SWCNT hybrids is strongly affected by the added content of SWCNTs. A good shape recovery of 88% could be obtained using PU–SWCNT hybrids containing 4% SWCNTs. That is, when 30 V was applied to the sample at 5 °C, the shape recovery time would only be 90 seconds.

Laser Cladding of Ni-Based Hardfacing Alloy Replacing Stellite06

For the disadvantages of Co element, such as rarity, high price and nuclear pollution, the Co-based materials will be eliminated in the valves which are used in the third and fourth-generation nuclear plants. In this paper, the composition of a Co-free Ni-based alloy was designed. With laser cladding technology, the Ni-based coatings were obtained. Microstructure of the coatings was characterized by optical microscopy (OM) and scanning electron microscopy (SEM). The phases in the surface layer were identified by X-ray diffraction (XRD) and energy-dispersive spectrometer (EDS). And the wear resistance of the coatings were tested and compared with Co-based alloy. The results showed that the coatings were mainly made of dendrite phases and interdendritic constituents. The dendrites were characterized of primary dendrites M7C3 and M23(CB)6 and some Ni3Al round particles uniformly dispersed in the γ-Ni matrix. There were a bit of Ni3B and Ni3Si phases in the coatings. The wear volume loss of Ni-based alloy was close to of Co-based alloy.

Comparative Study on Inorganic Composition and Crystallographic Properties of Cortical and Cancellous Bone

To comparatively investigate the inorganic composition and crystallographic properties of cortical and cancellous bone via thermal treatment under 700 °C. Thermogravimetric measurement, infrared spectrometer, X-ray diffraction, chemical analysis and X-ray photo-electron spectrometer were used to test the physical and chemical properties of cortical and cancellous bone at room temperature 250 °C, 450 °C, and 650 °C, respectively. The process of heat treatment induced an extension in the a-lattice parameter and changes of the c-lattice parameter, and an increase in the crystallinity reflecting lattice rearrangement after release of lattice carbonate and possible lattice water. The mineral content in cortical and cancellous bone was 73.2wt% and 71.5wt%, respectively. For cortical bone, the weight loss was 6.7% at the temperature from 60 °C to 250 °C, 17.4% from 250 °C to 450 °C, and 2.7% from 450 °C to 700 °C. While the weight loss for the cancellous bone was 5.8%, 19.9%, and 2.8 % at each temperature range, the Ca/P ratio of cortical bone was 1.69 which is higher than the 1.67 of stoichiometric HA due to the B-type CO₃²⁻ substitution in apatite lattice. The Ca/P ratio of cancellous bone was lower than 1.67, suggesting the presence of more calcium deficient apatite. The collagen fibers of cortical bone were arrayed more orderly than those of cancellous bone, while their mineralized fibers ollkded similar. The minerals in both cortical and cancellous bone are composed of poorly crystallized nano-size apatite crystals with lattice carbonate and possible lattice water. The process of heat treatment induces a change of the lattice parameter, resulting in lattice rearrangement after the release of lattice carbonate and lattice water and causing an increase in crystal size and crystallinity. This finding is helpful for future biomaterial design, preparation and application.

Effects of Different Gloss Firing Temperature on the Crystallization of Zinc-Based Crystal Glaze

Ceramic products with crystalline structure on its body give an artistic effect. The usage of zinc oxide which acts as a flux material has a beneficial effect in many colored glazes amongst which is crystalline glaze. Samples are fired at different gloss firing temperature of 1200oC to 1250oC for half an hour and hold for five hours at crystal growth temperature. After firing, the morphology of crystalline structure on the ceramic substrate body was identified using visual observation. The result show crystals start to develop at 1230oC of gloss firing temperature. Scanning Electron Microscope (SEM) analysis shows that these crystals are made of acicular needle shape crystals. X-ray Diffraction (XRD) and Energy Dispersive X-ray Spectrometer (EDX) analysis of the phases identified these crystals as willemite, Zn2SiO4 which formed spherulites. The results also show obvious growth and distance distribution between each of spherulites as the gloss firing temperatures increase to 1250oC.

High temperature friction and wear behaviour of sputter-deposited nanocrystalline (Mo xCr 1− x) 5Si 3 films by a double cathode glow discharge technique

In order to improve the wear resistance of titanium alloys, five kinds of sputter-deposited nanocrystalline (Mo x Cr 1− x ) 5Si 3( x = 1, 0.78, 0.75, 0.64, 0.57) films with average grain size 8 nm were fabricated on a substrate of Ti6Al4V alloy by means of a double cathode glow discharge technique. The microstructure and composition of the as-deposited films were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). Nanoindentation was used to measure hardness ( H) and elastic modulus ( E) of the as-deposited films. High temperature friction and wear properties of the as-deposited films were investigated against ZrO 2 ceramic balls by a ball-on-disk system at 600 °C. Compared with the Ti6Al4V alloy, the friction coefficient values of the nanocrystalline (Mo x Cr 1− x ) 5Si 3 films were reduced by 0.2–0.3, and specific wear rates decreased by two orders of magnitude and were around or lower than 10 −6 mm 3/(N m) at the load ranging from 3.3 N to 4.8 N. The friction coefficient and specific wear rates of the as-deposited films relied on the Cr content in the nanocrystalline (Mo x Cr 1− x ) 5Si 3 films, and the higher the Cr content, the lower friction coefficient and wear rates.

Synthesis and characterization of novel Ag-polypyrrole@poly(styrene-co-methacrylic acid) nanocomposite particles

Novel raspberry-like Ag-polypyrrole/poly(styrene-co-methacrylic acid) (Ag-PPy/P(St-co-MAA)) colloidal nanocomposite particles were prepared by aqueous oxidative polymerization of pyrrole using AgNO 3 as the oxidant. The polymerization was carried out in the pre-synthesized polymer-emulsion of P(St-co-MAA) with emulsifier-free P(St-co-MAA) latex particles serving as both the templates and the stabilizers. Without any extra surfactants or polymer stabilizers, the polymerization proceeded steadily with the in-situ produced Ag-PPy nanocomposites depositing on the surface of the template particles. The obtained product is typical of raspberry-like morphology, whose nanostructures and compositions were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and electron dispersive X-ray spectrometer (EDS), respectively. The results confirmed that the surface of the P(St-co-MAA) latex was coated by Ag-PPy nanocomposite particles with a size range from 2 nm to 50 nm. Most of Ag nanoparticles are encapsulated by the PPy sheath or dispersed in the PPy layer.

Effect of surfactants on morphology and luminescent properties of CaMoO 4: Eu 3+ red phosphors

Using polyethylene glycol (PEG), Tween-80, sodium dodecyl sulphonate (SAS) and cetyltrimethylammonium bromide (CTAB) as surfactants, CaMoO 4: Eu 3+ red phosphors were prepared by co-precipitation method and their morphology, structure and luminescent properties were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and fluorescence spectrometer. The results showed that the introduction of surfactants did not change the crystal structure of CaMoO 4: Eu 3+ phosphors, but greatly influenced their morphology. CaMoO 4: Eu 3+ red phosphors were prepared with 5 wt% PEG20000 having small-sized and regularly spherical morphology, and there were greater improvement in the luminescent intensity than phosphors prepared with other surfactants.

Growth and characterization of thermally evaporated ATO nanowires

The Sb-doped SnO 2 (ATO) nanowires have been synthesized on an alumina substrate using thermal evaporation with various growth durations of 1, 1.5 and 2 h. The morphology and structure of Sb-doped SnO 2 nanowires were characterized by a field emission scanning electron microscope (FESEM), an X-ray diffraction (XRD) spectrometer and a transmission electron microscope (TEM). Chemical composition and bonding were investigated by X-ray photoelectron spectroscopy (XPS), which shows that the Sb concentration of the nanowires increases with increasing growth durations. It is found that the electrical conductance of a single ATO nanowire- and nanowire films-based devices both increase with growth durations. Additionally, the photon-sensing measurement shows that the photon-sensing properties are improved with increasing growth durations, which provides a practicable method for the fabrication of ATO nanowire-based photodetectors.

Microstructure and dry sliding wear behavior of Fe 2TiSi /γ-Fe/Ti 5Si 3 composite coating fabricated by plasma transferred arc cladding process

Wear resistant Fe 2TiSi reinforced composite coating with a microstructure consisting of fine Fe 2TiSi primary dendrites uniformly distributed in the super fine γ-Fe/Ti 5Si 3 eutectic matrix was in situ fabricated on a substrate of 0.20%C plain low carbon steel substrate by the plasma transferred arc (PTA) cladding process using Fe–Ti–Si–Cr powders blend as the precursor material. Microstructure of the coating was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray energy dispersive spectrometer (EDS). Microhardness along the depth direction of the PTA clad Fe 2TiSi/γ-Fe/Ti 5Si 3 multi-phase composite coating was measured. Room temperature dry sliding wear resistance of the coating was tested. Results showed that the PTA clad Fe 2TiSi/γ-Fe/Ti 5Si 3 composite coating had high and almost uniform hardness distribution along the depth direction of the coating. Under dry sliding wear conditions at an ambient temperature, the PTA clad Fe 2TiSi/γ-Fe/Ti 5Si 3 composite coating exhibited excellent abrasive and adhesive wear resistance.

Electrical properties and interfacial reactions of rapidly annealed Ni/Ru Schottky rectifiers on n-type GaN

The effect of annealing temperature on the electrical and structural properties of Ni/Ru Schottky rectifiers have been investigated by current–voltage ( I– V), capacitance–voltage ( C– V), X-ray diffraction (XRD) and secondary ion mass spectrometer (SIMS) measurements. The measured Schottky barrier height for as-deposited Ni/Ru/n-GaN Schottky diode is 0.66 eV ( I– V) and 0.79 eV ( C– V). It is observed that the barrier height of the Ni/Ru Schottky contacts increases with an increase in annealing temperature. When the contact is annealed at 600 °C for 1 min in N 2 ambient, a maximum barrier height is achieved and the corresponding values are 0.79 eV ( I– V) and 0.98 eV ( C– V). It is observed that significant improvement in the electrical properties of Ni/Ru Schottky rectifier after annealing temperatures as compared to the as-deposited contact. Based on the results of SIMS and XRD, the formation of gallide phases at the Ni/Ru/n-GaN interface could be the reason for the increase of Schottky barrier height at elevated temperatures. Atomic force microscopy results showed that the surface morphology of the Ni/Ru Schottky contact is fairly smooth with a root-mean-square (RMS) roughness of 2.12 nm even after annealing at 600 °C. These results indicate that the Ni/Ru contacts could be attractive for high-temperature device applications.

Synthesis of novel high-voltage cathode material LiCoPO 4 via rheological phase method

For the first time, rheological phase method, a simple and effective route, is applied to synthesize novel cathode material LiCoPO 4. X-ray diffraction spectrometer (XRD), X-ray photoelectron spectrometer (XPS), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) are taken to investigate this material, respectively. XRD figure shows that the rheological sample is better crystallized than the solid-state one. XPS result of the rheological sample exhibits that the valence of Co is 2+. TEM images show that better dispersed particles with smaller size can be formed by rheological method comparing to the solid-state route. Charge–discharge test is carried out in the range of 3.0–5.0 V at 0.2 mA cm −2. The initial discharge capacity for rheological phase and solid-state powder is 71.5 and 30.9 mAh g −1, respectively. The better electrochemical property should be ascribed to the better crystallized rheological phase production with better dispersed and smaller particles, which can greatly facilitate the diffusion of Li +.

Oxidation and ignition behavior of a magnesium alloy containing rare earth elements

The oxidation and ignition behavior of Mg–8 wt.%Al alloy added with rare earth (RE) was investigated. When 0.1 wt.%RE was added, the ignition-proof effect was optimum and the ignition temperature of the alloy increased from 654°C to 823°C. The oxide scales and substrates of the alloy with 0.1 wt.%RE were characterized by scanning electronic microscope, X-ray diffraction, and energy dispersive spectrometer. The results show that a layer of tightly coherent oxidation film formed on the alloy surface under high temperature mainly consists of MgO, RE2O3, and Al2O3, which is about 2.5–3.5 µm thick. The oxidation kinetics curve of Mg–8 wt.%Al–0.1 wt.%RE follows the parabola rule at 400°C and 700°C and cubic rule at 600°C, which proves that the oxidation at these temperatures is controlled by diffusion obstruction so that the oxidation film can effectively restrain the alloy from further oxidation.

Influence of Annealing Temperatures on the Properties of Dual-Layer W-TiO<sub>2</sub> Thin Films

W-TiO2 (W, tungsten) dual-layer thin films are deposited by RF magnetron sputtering onto glass substrates and annealed at 150oC~400oC for 4hrs. The crystal structure, morphology, and trans- mittance of annealed W-TiO2 dual-layer thin films are investigated by X-ray diffraction, FESEM, and UV-Vis spectrometer, respectively. The annealing temperatures have large effect on the properties of W-TiO2 dual-layer thin films. The band gap energy values of W-TiO2 dual-layer thin films are evaluated from (h)1/2 versus energy plots. The energy gap for un-annealed W-TiO2 dual-layer thin film is 3.16 eV. As the annealing temperature increases from 150oC to 400oC, the energy gap decreases from 3.16 eV to 3.10 eV.

A Novel Technique of Flyash Utilization: Preparation of Silica from Flyash by Alkali Leaching

A new technique of flyash utilization was presented and high-purity silica was prepared by alkali leaching. The flyash was added into sodium hydroxide solution, and then the suspension was heated to 115 °C for 30 min. After filtrated, the filtrate was collected and carbon dioxide was imported into the solution. Finally, the silica would precipitate from the solution. The silica was characterized by scanning electron microscopy, X-ray diffraction and X-ray fluorescence spectrometer. The high-purity silica prepared from flyash was qualified for the rubber reinforcing agent used in shoemaking.

Synthesis and characterization of polycrystalline CuInS 2 thin films for solar cell devices at low temperature processing conditions

Polycrystalline CuInS 2 thin films were deposited on glass substrates using a novel solution-based continuous flow microreactor process for the first time. A series of analysis was performed to characterize the CuInS 2 thin films using UV–visible spectrophotometer, scanning electron microscope, X-ray diffraction spectrometer, and X-ray photoelectron spectroscopy. The estimated optical band gaps of CuInS 2 thin films were in the range of 1.52–1.60 eV. The structural and chemical binding information indicated that CuInS 2 thin films with a tetragonal chalcopyrite structure were successfully deposited. Dense film with a thickness around 1 μm could be obtained with a 5 min deposition time. This study demonstrates the solution-based continuous flow microreactor process is a promising low cost alternative for thin film PV manufacturing.

Wool keratin-stabilized silver nanoparticles

In this paper, we explored a facile method to prepare stable silver nanoparticles (Ag NPs) using extracted wool keratin as the capping agent. The formation of Ag NPs was investigated by UV–Vis spectroscopy, X-ray photo-electron spectrometer and X-ray diffraction spectrometer. The morphology of the NPs was detected by scanning electron microscopy in vacuum and atomic force microscopy in fluid. The possible interactions between the silver core and the capping agent have been investigated using Fourier transform infrared spectroscopy. The effects of keratin concentration on the incubation of the NPs were studied by UV–Vis spectra. It was found that under alkaline condition the process of incubation was much faster than that under neutral pH condition. The photoluminescence properties of the Ag NPs were also investigated. We believe that this work is helpful for the high-value utilization of wool and other keratin-rich bioresource.

Microstructural and microhardness characteristics of induction melted nickel-based alloys

Induction melted Ni-based alloys were fabricated by induction melting with different temperatures. To characterize the microstructure of the induction melted Ni-based alloy, the techniques of X-ray diffraction (XRD), X-ray mapping and wavelength dispersive spectrometer (WDS) were employed. The experimental results show that four morphologies, Ni 3Si + Ni 3B, γ-Ni + Ni 3Si, chromium borides and carbides, can be distinguished in the microstructure at all temperatures. Chromium carbides and borides are the hardest phases, while γ-Ni + Ni 3Si is the softest zone.