Electrochemical Formation of Elemental Boron in LiCl–KCl–KBF4 at 723 K

X Ray Diffraction ◽

Recycling Process ◽

Reduction Behavior ◽

X Ray ◽

Elemental Boron ◽

Transmission Electron ◽

Abstract The electrochemical reduction behavior of B(III) ions was investigated in LiCl–KCl–KBF4 at 723 K. The results of cyclic voltammetry using Mo, Ag, and Ni electrodes suggested the reduction of B(III) to B(0) at potentials of 1.5 V or at a more negative potential (vs. Li+/Li). Spherical electrodeposits were observed after potentiostatic electrolysis at 1.1–1.5 V. From the results of X-ray photoelectron spectroscopy, scanning transmission electron microscope/energy-dispersive X-ray spectroscopy (STEM/EDX), and selected area electron diffraction, it was concluded that the spherical electrodeposits obtained at 1.1 V were elemental amorphous boron. The purity of the products was 85 wt% boron, as determined by STEM/EDX analysis. The current efficiency of elemental B electrodeposition was 96.2% in this system. The formation of Ni2B at 1.1–1.9 V was indicated by X-ray diffraction, although it was not the main product. These results indicate that the presence of B(III) ions in a melt causes a fatal adverse effect on the recycling process of Nd–Fe–B magnets due to the reduction of B(III) ions. Further, the possibility of reducing the energy and cost of the elemental boron production process was discussed.

Hydrothermal Synthesis of Iodine-Doped Nanoplates with Enhanced Visible and Ultraviolet-Induced Photocatalytic Activities

International Journal of Photoenergy ◽

10.1155/2012/915386 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 5

Author(s):

Jiang Zhang ◽

Zheng-Hong Huang ◽

Yong Xu ◽

Feiyu Kang

Keyword(s):

Photocatalytic Activity ◽

Oxygen Vacancies ◽

Diffuse Reflectance Spectroscopy ◽

Synergetic Effect ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Photocatalytic Activities

The iodine-doped Bi2WO6(I-BWO) photocatalyst was prepared via a hydrothermal method using potassium iodide as the source of iodine. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of I-BWO for the degradation of rhodamine B (RhB) was higher than that of pure BWO and I2-BWO regardless of visible light (>420 nm) or ultraviolet light (<400 nm) irradiation. The results of DRS analysis showed that the I-BWO and I2-BWO catalysts had narrower band gaps. XPS analysis proved that the multivalent iodine species including I0and were coadsorbed on the defect surface of Bi2WO6in I-BWO. The enhanced PL intensity revealed that a large number of defects of oxygen vacancies were formed by the doping of iodine. The enhanced photocatalytic activity of I-BWO for degradation of RhB was caused by the synergetic effect of a small crystalline size, a narrow band gap, and plenty of oxygen vacancies.

Phase Transformation of Powdered Material by Using Metal Jet

Materials Science Forum ◽

10.4028/www.scientific.net/msf.706-709.741 ◽

2012 ◽

Vol 706-709 ◽

pp. 741-744 ◽

Cited By ~ 1

Author(s):

Akio Kira ◽

Ryuichi Tomoshige ◽

Kazuyuki Hokamoto ◽

Masahiro Fujita

Keyword(s):

Phase Transformation ◽

Powdered Material ◽

Ultrahigh Pressure ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Scanning Transmission ◽

Metal Jet ◽

Very High

The various techniques of phase transformation of the material have been proposed by many researchers. We have developed several devices to generate the ultrahigh pressure by using high explosive. One of them uses metal jets. It is expected that the ultrahigh pressure occurs by the head-on collision between metal jets, because the velocity of the metal jet is very high. By mixing a powdered material with metal jets, the pressure of the material becomes high. The purpose of this study is to transform the phase of the powdered material by using this high pressure. The powders of the graphite and hBN were applied. The synthesis to the diamond and cBN was confirmed by X-ray diffraction (XRD). In this paper, the mechanism of the generation of the ultrahigh pressure is explained and the results of the observation of the powder by using scanning transmission electron microscope (STEM) are reported.

A Facile Synthesis of CuInS2 Nanoparticles from Molecular Single Source Precursors

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2007.889 ◽

2007 ◽

Vol 7 (12) ◽

pp. 4353-4364 ◽

Cited By ~ 6

Author(s):

Dimple P. Dutta ◽

Garima Sharma ◽

A. K. Tyagi

Keyword(s):

Diffuse Reflectance ◽

Optical Band Gap ◽

Diffuse Reflectance Spectroscopy ◽

Reflectance Spectroscopy ◽

X Ray Diffraction ◽

Facile Synthesis ◽

X Ray ◽

Transmission Electron

CuInS2 nanoparticles have been synthesized via solvent thermolysis of novel bimetallic complexes of the general formula [(Ph3P)2 CuIn(S2COR)4] (where R = CH3; C2H5; C(CH3)2; and [(Ph3P)2 CuIn(SCH2CH2S)2]. These complexes have been prepared by the reactions of Na/KS2 COR and NaSCH2 CH2 SNa with InCl3 and [(Ph3 P)2 CuNO3] in methanol, respectively. Solvent thermolyses of these complexes were carried out in ethylene glycol at 196 °C for different time periods. The nanoparticles obtained were characterized extensively by techniques like powder X-ray diffraction, transmission electron microscopy, selected area electron diffraction, and X-ray photoelectron spectroscopy. The optical band gap of the nanoparticles was determined by diffuse reflectance spectroscopy (DRS).

A novel WC–W2C composite synthesis by arc plasma melt cast technique: microstructural and mechanical studies

SN Applied Sciences ◽

10.1007/s42452-020-04098-8 ◽

2021 ◽

Vol 3 (3) ◽

Author(s):

N. Nayak ◽

T. Dash ◽

D. Debasish ◽

B. B. Palei ◽

T. K. Rout ◽

...

Keyword(s):

Electron Microscopy ◽

Arc Plasma ◽

Micro Computed Tomography ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Bet Analysis ◽

Cast Technique

AbstractWC–W2C composites of three different compositions have been synthesized from mixture of WC + W (0, 5 and 16 wt% W) by thermal arc plasma melt-cast technique. Various grown phases observed in the composites consisting of major phases of WC and W2C and minor phases of unbound C (graphite) and tungsten (W) were confirmed by X-ray diffraction, selected area electron diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared studies. Transmission electron microscopy and field emission scanning electron microscopy show polycrystalline nature of composites. Energy dispersive spectroscopy (of X-ray) infers the absence of any impurity in the composite. Almost porous free nature of composites were observed from X-ray micro computed tomography and BET analysis studies. WC–W2C composite (16 wt% W) shows 25% and 21% higher micro hardness (2535 VHN) and Young’s modulus (625 GPa) values than that of pure melt cast WC sample.

Analytical Microscopic Analysis of Precipitates in Hastelloy Alloy C-276

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097922 ◽

1981 ◽

Vol 39 ◽

pp. 280-281

Author(s):

M. Raghavan ◽

B. J. Berkowitz ◽

J. C. Scanlon

Keyword(s):

Microscopic Analysis ◽

Second Phase ◽

Precipitation Reaction ◽

X Ray Diffraction ◽

Corrosion Properties ◽

X Ray ◽

Transmission Electron ◽

Second Phase Particles ◽

The present investigation was conducted to characterize the second phase particles in Hastelloy C-276 using an analytical Scanning Transmission Electron Microscope in order to understand their effect on the mechanical and Stress Corrosion properties of the alloy. Investigation in our 1aboratoryO) and previous published reports(2-4) have identified two types of precipitation reactions in this alloy. At temperatures in the range of 300-650°C, the alloy precipitates an ordered phase of the type Ni2(Cr, Mo)(1,2). This precipitation reaction is homogeneous with no preferential precipitation at the grain boundaries or twin boundaries. At temperatures above 650°C, several precipitate phases were observed to nucleate heterogeneously at boundaries and using X-ray diffraction techniques, the precipitates were previously identified as the μ, M6C and P phases(3-4). The present investigation was carried out to determine the composition of these second phase particles and this article describes the characterization of these precipitates using X-ray microanalysis and microdiffraction techniques.

Microstructure and Properties of Native Insulators Formed on Single Crystal Germanium

MRS Proceedings ◽

10.1557/proc-54-593 ◽

1985 ◽

Vol 54 ◽

Cited By ~ 2

Author(s):

O. J. Gregory ◽

E. E. Crisman ◽

J. Severns ◽

P. J. Stiles

Keyword(s):

Hexagonal Phase ◽

Far Infrared ◽

Infrared Transmission ◽

X Ray Diffraction ◽

X Ray ◽

Native Oxides ◽

Β Phase ◽

Transmission Electron ◽

ABSTRACTThe phases, morphologies and microstructures of native oxides and nitrides, grown on the vicinal planes of germanium, are discussed. Thermal oxides, formed under high pressure, were shown to be primarily amorphous for (100) and (110) oriented substrates and intermixed with a crystalline hexagonal phase on the (111) surfaces. Thermal treatments, in one atmosphere of flowing ammonia gas, converted oxide films to mixtures of nitrides and oxynitrides with the nitrides found to be combinations of a- and β-Ge3N4. The α-phase formed from condensation of vapors above the surface whereas the β-phase was a solid-solid reaction product which initiates at the oxide/germanium interface. These two processes appeared to proceed independently of each other. Results of low angle X-ray diffraction (XRD), far infrared transmission (FIRT), scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy (XPS) are discussed.

Phase Formation in a Wedged Au-Ag-Cu Multilayered Structure

MRS Proceedings ◽

10.1557/proc-311-39 ◽

1993 ◽

Vol 311 ◽

Cited By ~ 1

Author(s):

I. Goldfarb ◽

E. Zolotoyabko ◽

D. Shechtman

Keyword(s):

Electron Microscopy ◽

Phase Formation ◽

Multilayered Structure ◽

Heat Treatments ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Scanning Transmission ◽

Xrd Patterns

ABSTRACTAn advanced method for investigation of multicomponent systems is proposed. Thin wedged-shape films of pure components are subsequently deposited to form a multilayered structure with continuously-varying composition as a function of sample location, providing a large number of differently composed samples in one deposition run. Each sample is then subjected to various heat treatments, and phase content as well as the microstructure formed is under investigation.In this study an Au-Ag-Cu multilayered structure was sputtered at a room temperature onto 55 Formvar-coated Mo grids. The satellite-like X-Ray Diffraction (XRD) patterns of these samples revealed the formation of an artificial composition-modulated ternary superlattice, complete destruction of which was observed during heat treatments, where phase formation according to the ternary Au-Ag-Cu phase diagram took place.Several aspects of phase formation were analyzed using XRD, Electron Probe for Micro- Analysis (EPMA) in Scanning Electron Microscopy (SEM), and Scanning Transmission Electron Microscopy (STEM) combined with Selected Area Electron Diffraction (SAED), Digital X-Ray Mapping (DXM), Secondary Electron Mapping and EPMA methods.

High-resolution x-ray imaging of small copper-rich precipitates in steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104704 ◽

1988 ◽

Vol 46 ◽

pp. 528-529

Author(s):

J. R. Michael ◽

K. A. Taylor

Keyword(s):

Electron Microscopy ◽

Thermomechanical Processing ◽

Atom Probe ◽

Ferrite Matrix ◽

Probe Field ◽

X Ray ◽

Subsequent Transformation ◽

Transmission Electron ◽

Although copper is considered an incidental or trace element in many commercial steels, some grades contain up to 1-2 wt.% Cu for precipitation strengthening. Previous electron microscopy and atom-probe/field-ion microscopy (AP/FIM) studies indicate that the precipitation of copper from ferrite proceeds with the formation of Cu-rich bcc zones and the subsequent transformation of these zones to fcc copper particles. However, the similarity between the atomic scattering amplitudes for iron and copper and the small misfit between between Cu-rich particles and the ferrite matrix preclude the detection of small (<5 nm) Cu-rich particles by conventional transmission electron microscopy; such particles have been imaged directly only by FIM. Here results are presented whereby the Cu Kα x-ray signal was used in a dedicated scanning transmission electron microscope (STEM) to image small Cu-rich particles in a steel. The capability to detect these small particles is expected to be helpful in understanding the behavior of copper in steels during thermomechanical processing and heat treatment.

The effect of small additions of Cu on precipitation in Al-Mg-Si alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135812 ◽

1990 ◽

Vol 48 (2) ◽

pp. 442-443

Author(s):

M. Tamizifar ◽

G. Cliff ◽

R.W. Devenish ◽

G.W. Lorimer

Keyword(s):

Electron Microscopy ◽

Analytical Electron Microscopy ◽

Argon Atmosphere ◽

Age Hardening ◽

X Ray ◽

Transmission Electron ◽

Heat Treated ◽

Analytical Electron ◽

Small additions of copper, <1 wt%, have a pronounced effect on the ageing response of Al-Mg-Si alloys. The object of the present investigation was to study the effect of additions of copper up to 0.5 wt% on the ageing response of a series of Al-Mg-Si alloys and to use high resolution analytical electron microscopy to determine the composition of the age hardening precipitates.The composition of the alloys investigated is given in Table 1. The alloys were heat treated in an argon atmosphere for 30m, water quenched and immediately aged either at 180°C for 15 h or given a duplex treatment of 180°C for 15 h followed by 350°C for 2 h2. The double-ageing treatment was similar to that carried out by Dumolt et al. Analyses of the precipitation were carried out with a HB 501 Scanning Transmission Electron Microscope. X-ray peak integrals were converted into weight fractions using the ratio technique of Cliff and Lorimer.

High Spatial Resolution Compositional Analysis at Interfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001513 ◽

1980 ◽

Vol 38 ◽

pp. 356-359

Author(s):

John B. Vander Sande ◽

Thomas F. Kelly ◽

Douglas Imeson

Keyword(s):

Electron Microscope ◽

High Spatial Resolution ◽

Compositional Analysis ◽

Thin Specimen ◽

X Ray ◽

Volume Of Interest ◽

Transmission Electron ◽

Scanning Transmission ◽

Electron Energy Loss

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.