scholarly journals Phase Transformation of Doped LiCoPO4 during Galvanostatic Cycling

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3810
Author(s):  
Wen Zhu ◽  
Dongqiang Liu ◽  
Catherine Gagnon ◽  
Vincent Gariépy ◽  
Michel L. Trudeau ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Reaction Pathway ◽  
Intermediate Compound ◽  
Discharge Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Changes ◽  
Biphasic Reaction ◽  
C 30 ◽  
Ray Patterns

In situ X-ray diffraction was employed to investigate the crystal structure changes in Cr/Si co-doped Li(Co,Fe)PO4 cathode material during a galvanostatic charge/discharge process at a slow rate of C/30. The evolution of the X-ray patterns revealed that the phase transformation between the Cr/Si-Li(Co,Fe)PO4 and Cr/Si-(Co,Fe)PO4 is a two-step process, which involves the formation of an intermediate compound of Cr/Si-Li0.62(Co,Fe)PO4 upon the extraction of Li ions from the pristine phase. Different from the previously reported two biphasic transition steps, the phase transformation of the Cr/Si-Li(Co,Fe)PO4 followed a solid solution and a biphasic reaction pathway at different stages of the delithiation/lithiation process, respectively.

scholarly journals Phase Transformation of Alumina, Silica and Iron Oxide during Carbothermic Reduction of Fly Ash for Ceramics Production

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1165
Author(s):  
Qingchun Yu ◽  
Yong Deng ◽  
Yuebin Feng ◽  
Ziyong Li
Keyword(s):  
Phase Transformation ◽  
Fly Ash ◽  
Carbothermic Reduction ◽  
Energy Dispersive Spectrometry ◽  
Intermediate Compound ◽  
Added Value ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduced Products ◽  
Electronic Microscope

Fly ash is a by-product from burning of coal. Utilization of fly ash by carbothermic reduction is an effective way to recover aluminum, silicon, and iron to enhance product-added value. This work is focused on the phase transformation of Al2O3, SiO2 and Fe2O3 during carbothermic reduction of fly ash in air. A comparative analysis of carbothermic reduction of fly ash in air and in nitrogen was made. Thermodynamics analysis was performed to illustrate the possible reactions for residue and condensate. X-ray diffraction (XRD), scanning electronic microscope (SEM), and energy dispersive spectrometry (EDS) were employed to characterize the phase composition, surface morphology, and microstructure of the reduced products. Results show that Fe3Si and Fe2Si appear sequentially with increasing of temperature. Al5O6N is an intermediate compound. Residue of Al9FeSi3, Al, and Si, and condensate of SiC, AlN and C are obtained. β-SiAlON was not found in the residue. Nitrogen is involved in the reduction of Al2O3 but not in the reduction of SiO2 and Fe2O3. Carbothermic reduction of fly ash in air did not behave the same as fly ash in nitrogen.

X-Ray Diffraction and Barkhausen Noise Diagnostics of Thick Welds Prepared by Metal Active Gas and Laser Welding

2016 ◽  
Vol 827 ◽  
pp. 113-116 ◽  
Author(s):  
Kamil Kolařík ◽  
Nikolaj Ganev ◽  
Karel Trojan ◽  
Ondřej Řídký ◽  
Lukáš Zuzánek ◽  
...  
Keyword(s):  
Noise Analysis ◽  
Real Structure ◽  
Barkhausen Noise ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Changes ◽  
Rs Analysis ◽  
Noise Diagnostics ◽  
Non Destructive ◽  
Power Diode

Non-destructive methods for detection and measurement of residual stresses (RS) have been increasingly used in the last few years. The paper outlines the capability of Barkhausen noise analysis (BNA) for evaluation of real structure changes and RS on cross-section of welds due to welding of ferromagnetic plates compared with X-ray diffraction (XRD). The purpose of this study is to evaluate the RS distribution of specimens joined using by high power diode laser and metal active gas (MAG) welding that can be used for quantitative analysis of macro and micro level RS separately. The principal advantages of BNA over XRD as a tool for RS analysis and real structure characterisation are that it is mobile, faster with more facile carrying out and hence BNA is frequently used for continuous monitoring of RS in industrial processes.

scholarly journals Nanocrystal, phase transformation and microstructure of Ni50Ti50 shape memory alloy

2018 ◽  
Vol 24 (02) ◽  
pp. 22-25
Author(s):  
Dovchinvanchig M ◽  
Chunwang Zhao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
One Step ◽  
Niti Matrix ◽  
Electronic Microscope

The nanocrystal, phase transformation and microstructure behavior of Ni50Ti50 shape memory alloy was investigated by scanning electronic microscope, X-ray diffraction and differential scanning calorimetry. The results showed that the microstructure of Ni-Ti binary alloy consists of the NiTi2 phase and the NiTi matrix phase. One-step phase transformation was observed alloy.

scholarly journals X-RAY DIFFRACTION STUDIES ON AMYLOID FILAMENTS

1968 ◽  
Vol 16 (11) ◽  
pp. 673-677 ◽  
Author(s):  
E. D. EANES ◽  
G. G. GLENNER
Keyword(s):  
Polypeptide Chain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Filament Axis ◽  
Adjacent Chain ◽  
Diffuse Halo ◽  
Sheet Structure ◽  
Regular Manner ◽  
Ray Patterns ◽  
Pleated Sheet

The filamentous protein component of amyloid-laden tissue was studied by x-ray diffraction procedures. The principal features of the x-ray pattern from nonoriented amyloid material consist of a sharp, intense ring at 4.75 Å overlaying a diffuse halo at 4.3 Å, and a broad and less intense ring at 9.8 Å. When oriented, the material gives a "cross-β" x-ray pattern. The x-ray findings are interpreted in terms of a "pleated sheet" structure formed by the amyloid polypeptide chain folding in a regular manner on itself such that adjacent chain segments are laterally arranged in an antiparallel manner. The x-ray patterns from oriented amyloid suggest further that the axes of the chain segments run transverse to the filament axis.

Phase Transformation of Powdered Material by Using Metal Jet

2012 ◽  
Vol 706-709 ◽  
pp. 741-744 ◽  
Author(s):  
Akio Kira ◽  
Ryuichi Tomoshige ◽  
Kazuyuki Hokamoto ◽  
Masahiro Fujita
Keyword(s):  
Phase Transformation ◽  
Powdered Material ◽  
Scanning Transmission Electron Microscope ◽  
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.

Using Ultrathin-Film, Modulated Composites to Control the Reaction Mechanism of Ternary Compound Formation

1991 ◽  
Vol 238 ◽  
Author(s):  
Loreli Fister ◽  
David C. Johnson
Keyword(s):  
Ternary Compound ◽  
Reaction Pathway ◽  
Experimental Parameter ◽  
Ultrathin Film ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Compound Formation ◽  
One Dimensional ◽  
X Ray ◽  
Made In

ABSTRACTA predictable, controllable approach to the synthesis of ternary compounds through known intermediates is presented. Thin and ultrathin film superlattices were made in the Mo-Se, Cu-Se and Mo-Cu systems. Differential scanning calorimetry, low- and high-angle x-ray diffraction were used to assess the interdiffusion and nucleation reactions between elemental layers in these one-dimensional crystals. The experimental parameter modulation distance was used to influence the interfacial reactions. The results from each binary system were then used to predict the reaction pathway in the synthesis of a ternary compound, Cu2Mo6Se8. Superlattices with two different lengthscales were investigated. In the first, only one intermediate, MoSe2 which typically crystallizes at ∼200'C, is observed prior to the crystallization of Cu2Mo6Se8. In the second, no crystalline intermediates are observed below 6000 C.

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