Sparse X-ray hyperspectral tomography for nanoscopic compositional analysis of VPO catalysts

In the scanning transmission electron microscope (STEM) a fine probe of electrons is scanned across the thin specimen, or the probe is stationarily placed on a volume of interest, and various products of the electron-specimen interaction are then collected and used for image formation or microanalysis. The microanalysis modes usually employed in STEM include, but are not restricted to, energy dispersive X-ray analysis, electron energy loss spectroscopy, and microdiffraction.

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Synthesis and Characterization of CdSe Nanoparticles with Cadmium Precursor Variation in Colloidal Synthesis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.976.52 ◽

2014 ◽

Vol 976 ◽

pp. 52-58 ◽

Cited By ~ 1

Author(s):

Janeth Sarmiento Arellano ◽

Enrique Rosendo ◽

Román Romano ◽

Gabriela Nieto ◽

Tomás Díaz ◽

...

Keyword(s):

Aqueous Solution ◽

Ph Value ◽

Sodium Tripolyphosphate ◽

Compositional Analysis ◽

Cadmium Acetate ◽

Cdse Nanoparticles ◽

Molar Concentration ◽

Colloidal Synthesis ◽

Cadmium Nitrate ◽

X Ray

A comparative study of the synthesis of cadmium selenide (CdSe) nanoparticles (NPs) using different cadmium precursors such as, cadmium nitrate (Cd (NO3)2·4H2O), cadmium acetate ((CH3COO)2Cd·2H2O) and cadmium chloride (CdCl2·2.5H2O) is presented in this work. The method used to obtain the CdSe NPs was the colloidal synthesis at low temperature and atmospheric pressure. The Cd2+ ions were obtained in aqueous solution at room temperature, the surfactant used in the process was an aqueous solution of sodium hydroxide (NaOH), penta-sodium tripolyphosphate and H2O named commonly extran, which not only helps to stabilize the NPs, but also allows adjusting the pH of the solution. Se2- ions were obtained with sodium borohydride (NaBH4) as reductant at 75 oC. The by-products from the reaction were eliminated through a cleaning process with hydrochloric acid (HCl). Molar concentration of Cd:Se was varied from 3:1 to 1:3 and the pH value was varied between 8 and 11. The obtained samples were characterized by X-ray diffraction (XRD), it was seen that the obtained NPs present cubic centered face structure. The crystallite size from the powder was calculated using the Debye-Scherrer equation and was found between 3.3 nm and 5.6 nm, the variation in size depends on the molar concentration of cadmium and selenium. Morphological study was done using scanning electron microscopy (SEM) and compositional analysis was done by energy dispersive x-ray analysis (EDAX).

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Modification of structural and dielectric properties of polycrystalline Gd-doped BFO–PZO

Journal of Advanced Dielectrics ◽

10.1142/s2010135x18500315 ◽

2018 ◽

Vol 08 (05) ◽

pp. 1850031 ◽

Cited By ~ 1

Author(s):

Ambika Ray ◽

Banarji Behera ◽

Tanmoy Basu ◽

Saumitra Vajandar ◽

Santosh Kumar Satpathy ◽

...

Keyword(s):

Dielectric Properties ◽

Boundary Effect ◽

Ion Beam ◽

Ferroelectric Properties ◽

Compositional Analysis ◽

Structural Defects ◽

X Ray ◽

Dielectric Constant And Loss ◽

Before And After ◽

Lcr Meter

[Formula: see text](BiFe[Formula: see text]GdxO3)–y(PbZrO3) composites [Formula: see text], having four different Gd concentrations ([Formula: see text], 0.1, 0.15, and 0.2), were synthesized and their structural, dielectric, and ferroelectric properties have been studied using different characterization techniques. In addition, to investigate the effect of ion implantation on the microstructure and dielectric properties, these composites were exposed to 2[Formula: see text]MeV He[Formula: see text]-ions. Modifications of the structure, surface morphology and electrical properties of the samples before and after ion exposure were demonstrated using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) technique, and LCR meter. The compositional analysis was carried out using energy dispersive X-ray spectrometry (EDS). XRD results demonstrated a decrease in the intensity profile of the dominant peak by a factor of 6 showing a degradation of the crystallinity. Willliamson–Hall (WH) plots reveal reduction in the grain size after irradiation along with an increase in strain and dislocation density. A decrease in the dielectric constant and loss has been recorded after ion beam exposure with reduction in ac conductivity value. The contribution of grain and grain boundary effect in conduction mechanism has been addressed using Nyquist plots. All the samples demonstrate a lossy ferroelectric loop which shows a clear modification upon irradiation. The role of structural defects modifying the physical properties of the composite materials is discussed in this work.

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Enhancement of the Mechanical Properties in Al–Si–Cu–Fe–Mg Alloys with Various Processing Parameters

Materials ◽

10.3390/ma11112150 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2150 ◽

Cited By ~ 3

Author(s):

Su-Seong Ahn ◽

Sharief Pathan ◽

Jar-Myung Koo ◽

Chang-Hyun Baeg ◽

Chan-Uk Jeong ◽

...

Keyword(s):

Mechanical Properties ◽

Electron Microscope ◽

Silicon Content ◽

Compositional Analysis ◽

Processing Parameters ◽

Silicon Phase ◽

X Ray ◽

Primary Si ◽

Transmission Electron ◽

Eutectic Si

In this research, various processing conditions were implemented to enhance the mechanical properties of Al-Si alloys. The silicon content was varied from hypoeutectic (Si-10 wt.%) to eutectic (Si-12.6 wt.%) and hypereutectic (Si-14 wt.%) for the preparation of Al-XSi-3Cu-0.5Fe-0.6 Mg (X = 10–14%) alloys using die casting. Subsequently, these alloys were hot-extruded with an optimum extrusion ratio (17:1) at 400 °C to match the output extruded bar to the compressor size. An analysis of the microstructural features along with a chemical compositional analysis were carried out using scanning electron microscope along with energy dispersive X-ray spectroscopy and transmission electron microscope. The SEM micrographs of the extruded samples displayed cracks in primary Si, and the intermetallic (β-Al5FeSi) phase was fragmented accordingly. In addition, the silicon phase was homogenously distributed, and the size remained constant. The mechanical properties of the extruded samples were enhanced by the increase of silicon content, and consequently the ductility decreased. By implementing proper T6 heat treatment parameters, coherent Al2Cu phases were formed in the Al matrix, and the Si phase was gradually increased along with the silicon content. Therefore, high tensile strength was achieved, reaching values for the Al-XSi-3Cu-0.5Fe-0.6Mg (X = 10–14%) alloys of 366 MPa, 388 MPa, and 420 MPa, respectively.

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Growth kinetics and compositional analysis of silicon rich a-SiNx:H film: A soft x-ray reflectivity study

Applied Physics Letters ◽

10.1063/1.3497284 ◽

2010 ◽

Vol 97 (15) ◽

pp. 151906 ◽

Cited By ~ 17

Author(s):

Sarab Preet Singh ◽

Mohammed H. Modi ◽

P. Srivastava

Keyword(s):

Growth Kinetics ◽

Compositional Analysis ◽

X Ray

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Near Edge X-Ray Absorption Fine Structure (NEXAFS) Microscopy: Chemical Analysis at Sub Visible Spatial Resolution

Microscopy and Microanalysis ◽

10.1017/s1431927600011144 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 851-852

Author(s):

H. Ade

Keyword(s):

Fine Structure ◽

Compositional Analysis ◽

High Sensitivity ◽

Linear Dichroism ◽

X Rays ◽

X Ray ◽

Absorption Fine ◽

Nexafs Spectroscopy ◽

Wide Range ◽

X Ray Absorption

Infrared, Raman, and fluorescence/luminescence microspectroscopy/microscopy in many instances seek to provide high sensitivity compositional and functional information that goes beyond mere elemental composition. This goal is shared by NEXAFS microscopy, in which Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy is employed to provide chemical sensitivity and can be relatively easily adopted in a scanning transmission x-ray microscope (STXM). In addition to compositional information, NEXAFS microscopy can exploit the dependence of x-ray absorption resonances on the bond orientation relative to the linearly polarized x rays (linear dichroism microscopy). For compositional analysis, NEXAFS microscopy is analogous to Electron Energy Loss Spectroscopy (EELS) in an electron microscope. However, when utilizing near edge spectral features, NEXAFS microscopy requires a considerable lower dose than EELS microscopy which makes it very suitable to studying radiation sensitive materials such as polymers. NEXAFS has shown to have excellent sensitivity to a wide range of moieties in polymers, including sensitivity to substitution isomerism.

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GaxIn1-xP/GaP Heterostructures on Si(001) Substrate

MRS Proceedings ◽

10.1557/proc-441-81 ◽

1996 ◽

Vol 441 ◽

Author(s):

N. Sukidi ◽

N. Dietz ◽

U. Rossow ◽

K. J. Bachmann

Keyword(s):

Compositional Analysis ◽

Chemical Beam Epitaxy ◽

X Ray Diffraction ◽

Tem Analysis ◽

Cross Sectional ◽

Temperature Growth ◽

X Ray ◽

Vegard’S Law ◽

Graded Interlayer ◽

Source Materials

AbstractIn this contribution we report on the real-time monitoring of low temperature growth of epitaxial GaxIn1-xP/GaP heterostructures on Si(100) by pulse chemical beam epitaxy, using tertiary butylphosphine (TBP), triethylgallium (TEG), and trimethylindium (TMI) as source materials. Both step-graded and continuously graded heterostructures have been investigated. The composition of the GaxIn1-xP epilayers has been analyzed by various techniques including X-ray diffraction, Rutherford backscattering, Auger, and Raman spectroscopy. Good correlation has been found between X-ray diffraction, RBS, and Vegard's law compositional analysis. We used Ppolarized Reflectance Spectroscopy (PRS) and Laser Light Scattering (LLS) to monitor the growth rate and surface morphology during growth. The information gained by these techniques has been utilized in the improvement of the surface preconditioning as well as to optimize the initial heteroepitaxial nucleation and overgrowth process. We studied the optical response to the compositional changes in the surface reaction layer (SRL) during the exposure of the surface to either sequential or synchronous pulses of TEG and TMI. The cross sectional TEM analysis indicates that the synchronous exposure results in an abrupt GaxIn1-xP/GaP interface while the sequential exposure does not which may suggest a compositionally graded interlayer formation. For heteroepitaxial GaxIn1-xP films on Si, a buffer layer of GaP is found to be necessary for optimum uniformity of the GaxIn1-xP layer. The selective growth of GaxIn1-xP on Si(001) is accessed.

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Correction. Compositional Analysis ofnComponent Systems by X-Ray Absorption Method

Analytical Chemistry ◽

10.1021/ac60221a030 ◽

1965 ◽

Vol 37 (2) ◽

pp. 258-258 ◽

Cited By ~ 1

Author(s):

Robert. Lefker

Keyword(s):

Compositional Analysis ◽

Absorption Method ◽

X Ray ◽

X Ray Absorption

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Vibrational and Compositional Analysis Associated with the Color ofGuadua angustifoliaKunth Variety Bicolor (GAKVB)

Advances in Materials Science and Engineering ◽

10.1155/2014/429314 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8

Author(s):

J. I. Cárdenas ◽

C. Vargas-Hernandez

Keyword(s):

Organic Dyes ◽

Compositional Analysis ◽

Immersion Test ◽

Central American ◽

Energy Dispersive ◽

Solid State Reactions ◽

Aluminum Oxides ◽

X Ray ◽

Color Changes ◽

Indigo Blue

The vibrational modes and compositional behavior of plant material ofGuadua angustifoliaKunth Variety Bicolor (GAKVB) and the characteristics associated with color changes were evaluated by Raman, infrared, and energy-dispersive X-ray spectroscopy. In the vibrational spectra, the frequencies of 1598, 2099, and 845 cm−1were associated with yellow and blue pigments. These pigments can be found in natural organic dyes of vegetable origin, such as indigo blue (anil or pastel), extracted from Central American shrubs (Indigoferaand indaco) (Domenech, 2010), in some pigments synthesized in solid-state reactions from aluminum oxides, such as CaAl12O19, that have a turquoise color (Costa et al., 2009), and in Indian yellow (MgC19H16O11·5H2O). Using an immersion test, it was shown that the color was stable and that no loss of color occurred when photosynthesis was halted in the sample. The green and yellow stripes are assigned to Fe, N, Mg, and Si compounds. The yellow is due to decrease of Fe, Mg, and elemental Si. Results are obtained using energy-dispersive X-ray spectroscopy and Raman measurements.

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SYNTHESIS AND PIXE CHARACTERIZATION OF CuInSe2 AND CuIn3Se5

International Journal of PIXE ◽

10.1142/s0129083506000885 ◽

2006 ◽

Vol 16 (01n02) ◽

pp. 127-136

Author(s):

P. MALAR ◽

TAPASH RANJAN RAUTRAY ◽

V. VIJAYAN ◽

S. KASIVISWANATHAN

Keyword(s):

Electron Microscopy ◽

Single Phase ◽

Compositional Analysis ◽

X Ray Diffraction ◽

Stoichiometric Mixture ◽

X Ray ◽

Transmission Electron ◽

Xrd Studies ◽

Constituent Elements

Polycrystalline ingots of CuInSe 2 and CuIn 3 Se 5 were synthesized by melt-quench technique starting from the stoichiometric mixture of constituent elements. X-ray Diffraction (XRD) studies confirmed the single-phase nature of the materials. Compositional analysis by Particle Induced X-ray Emission (PIXE) showed that the compounds are near stoichiometric. Thin films of CuInSe 2 and CuIn 3 Se 5 were grown from pre-synthesized CuInSe 2 and CuIn 3 Se 5 powders. The films were polycrystalline, single-phase and near stoichiometric in nature, as indicated by Transmission Electron Microscopy (TEM) and PIXE studies.

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