Structural characterization of carbons obtained from polyparaphenylenes prepared by the Kovacic and Yamamoto methods

1998 ◽  
Vol 13 (7) ◽  
pp. 2023-2030 ◽  
Author(s):  
M. Endo ◽  
C. Kim ◽  
T. Hiraoka ◽  
T. Karaki ◽  
K. Nishimura ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Layer Structure ◽  
Treatment Temperature ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Crystallite Structure ◽  
Li Ion

The structure of polyparaphenylene (PPP)-based carbons prepared by the Kovacic and Yamamoto methods heat-treated at 650–3000 °C have been characterized comparatively by using x-ray diffraction, SEM, TEM, and Raman spectroscopy. Both kinds of carbons indicate not typical but poor graphitizing behavior, especially for the case of PPP Yamamoto samples, and much less for PPP Kovacic samples, by heat treatment up to 3000 °C. The Kovacic-based samples heat-treated at 600–2400 °C have a more developed layer structure than that of Yamamoto-based samples. In contrast, for HTT's (heat-treatment temperature) more than about 2400 °C, PPP Yamamoto-based carbons exhibit a more developed crystallite structure than PPP Kovacic-based carbons. At a given HTT, PPP Kovacic-based carbons have a much more quinoid-like structure and graphene-type structure than PPP Yamamoto-based carbons, as indicated by the carbon yield and Raman scattering measurements. It is suggested that the detailed structure of the starting polymers influences the texture as well as the microstructure of resultant carbons even though both are obtained from the same kinds of precursors. These microstructures also largely influence the anode performance when these carbons are used in Li ion batteries.

Neodymium Incorporation in Zirconolite-Based Glass-Ceramics

2000 ◽  
Vol 663 ◽  
Author(s):  
P. Loiseau ◽  
D. Caurant ◽  
N. Baffier ◽  
C. Fillet
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Fission Products ◽  
Treatment Temperature ◽  
Spent Fuel ◽  
X Ray Diffraction ◽  
Parent Glass ◽  
X Ray ◽  
Spin Resonance

ABSTRACTThe investigations on enhanced reprocessing of nuclear spent fuel, and notably on separating the long-lived minor actinides, such as Am and Cm, from the other fission products have led to the development of highly durable specific matrices such as glass-ceramics for their immobilization. This study deals with the characterization of zirconolite (CaZrTi2O7) based glass-ceramics synthesized by devitrification of an aluminosilicate parent glass. Trivalent actinide ions were simulated by neodymium, which is a paramagnetic local probe. Glass-ceramics with Nd2O3 contents ranging from 0 to 10 weight % were prepared by heat treatment of a parent glass at two different growth temperatures: 1050° and 1200°C. X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and electron spin resonance (ESR) measurements clearly indicate that Nd3+ ions are partly incorporated in zirconolite crystals formed in the bulk of the glass-ceramic samples. The amount of neodymium in the crystalline phase was estimated using ESR results and was found to decrease with increasing either heat treatment temperature or total Nd2O3 content.

scholarly journals Electrochemical and electron microscopic characterization of Super-P based cathodes for Li–O2 batteries

2013 ◽  
Vol 4 ◽  
pp. 665-670 ◽  
Author(s):  
Mario Marinaro ◽  
Santhana K Eswara Moorthy ◽  
Jörg Bernhard ◽  
Ludwig Jörissen ◽  
Margret Wohlfahrt-Mehrens ◽  
...  
Keyword(s):  
Lithium Salt ◽  
Electrochemical Impedance ◽  
Ex Situ ◽  
Cathode Side ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Li Ion

Aprotic rechargeable Li–O2 batteries are currently receiving considerable interest because they can possibly offer significantly higher energy densities than conventional Li-ion batteries. The electrochemical behavior of Li–O2 batteries containing bis(trifluoromethane)sulfonimide lithium salt (LiTFSI)/tetraglyme electrolyte were investigated by galvanostatic cycling and electrochemical impedance spectroscopy measurements. Ex-situ X-ray diffraction and scanning electron microscopy were used to evaluate the formation/dissolution of Li2O2 particles at the cathode side during the operation of Li–O2 cells.

Morphology of Carbon Micro-Coils

2004 ◽  
Vol 449-452 ◽  
pp. 205-208
Author(s):  
M. Fujii ◽  
S. Motojima
Keyword(s):  
Heat Treatment ◽  
Lattice Structure ◽  
Diffraction Method ◽  
Chemical Vapor ◽  
Amorphous Structure ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Higher Temperature

The double helical carbon micro-coils were obtained by chemical vapor deposition. As-grown carbon micro-coils with amorphous structure were heat-treated at various temperatures up to 3000°C . By heat treatment, the shape of the coils was not changed. The morphology of these coils was observed in detail using electron microscope. The lattice structure was analyzed by X-ray diffraction method. Heat treatment temperature dependence of the magnetoresistance and the measurement of Raman spectra suggest that the coils heattreated at higher temperature are more highly graphitized.

Preparation and Characterization of β-Eucryptite Glass Ceramics

2012 ◽  
Vol 624 ◽  
pp. 134-137 ◽  
Author(s):  
Ping Zhai ◽  
Xiao Feng Duan ◽  
Da Qian Chen ◽  
Chong Hai Wang
Keyword(s):  
Heat Treatment ◽  
Expansion Coefficient ◽  
Heat Treatment Temperature ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Solid Reaction ◽  
X Ray

In this paper, β-eucryptite glass ceramics were synthesized by using solid reaction method. Phase constitution, structure and properties of the material were studied by X-ray diffraction (XRD) and differential thermal analysis (DTA). Furthermore, the effects of heat treatment temperature and preservation time on the thermal expansion coefficient were also analyzed. The results showed that the crystallization temperature of β-eucryptite glass ceramics was in the range of 810-860 °C and the content was more than 90%. With the increase of heat treatment temperature, the material expansion coefficient decreased.

Sol-gel Synthesis, Magnetic and Structural Characterization of BaFe11.6–2xMxTixO19 (M=Co, Zn, Sn) Compounds.

2002 ◽  
Vol 755 ◽  
Author(s):  
G. Mendoza-Suárez ◽  
A.F. Fuentes ◽  
J.I. Escalante-García ◽  
O.E. Ayala-Valenzuela
Keyword(s):  
Magnetocrystalline Anisotropy ◽  
Sol Gel ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Barium Ferrites ◽  
Crystallite Sizes ◽  
Sol Gel Synthesis

ABSTRACTSubstituted barium ferrites powders with Ti4+-M2+ (M = Co, Zn, Sn) cationic mixtures were prepared by a sol-gel route. The materials were heat-treated in the range 925–1000 °C and characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The results showed that the effect of the substitution, x was to lower the coercivity (Hc), owing to the decrease of the magnetocrystalline anisotropy of the magnetoplumbite structure of the BaM. In this regard Sn-Ti substitutions tended to decrease Hc more rapidly than Zn-Ti and Ti-Co substitutions, in that order. Regarding the saturation magnetization (Ms), Zn-Ti mixtures showed slightly better Ms than Ti-Co substitutions; however, the Sn-Ti showed a more marked decrease as x increased. As revealed by SEM, the effect of the heat-treatment temperature was to increase the volume of multi-domain particles, following a Hc decrease due to grain coarsening. Contrarily, as a result of the improved crystallinity of the samples, as observed from the XRD peaks, Ms enhancement was recorded. Crystallite sizes decreased below 100 nm as x increased, although it was also dependent on the cationic mixture. In this respect Sn-Ti substitutions needed higher treatment temperatures to yield materials with adequate crystallinity and phase constitution.

Precipitate Phases and Mechanical Properties of Heat-Treated ASTM F 90 Co-Cr-W-Ni Alloy

2014 ◽  
Vol 616 ◽  
pp. 258-262 ◽  
Author(s):  
Kosuke Ueki ◽  
Kyosuke Ueda ◽  
Takayuki Narushima
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Biomedical Applications ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Precipitation Behavior ◽  
X Ray ◽  
Phase Precipitate ◽  
Heat Treated ◽  
Ni Alloy

The precipitation behavior during heat treatment and resulting mechanical properties of ASTM F 90 Co-20Cr-15W-10Ni (mass%) alloys were investigated with regards to their biomedical applications. Heat treatment was conducted at temperatures of 873 to 1623 K, for a holding time of 259.2 ks. The precipitates produced were then electrolytically extracted from the alloys and analyzed by X-ray diffraction (XRD). This revealed that the precipitates formed were an M23X6 type and/or η-phase (i.e., an M6X-M12X type). The M23X6-type precipitate was detected across the entire heat-treatment temperature range; however, the η-phase precipitate was only detected at 1073 to 1473 K, becoming dominant at 1173 to 1373 K. The formation of M23X6 type precipitates at 873 K is shown to improve the mechanical properties of this alloy, whereas the domination by the η-phase precipitate at higher temperatures causes deterioration in the ductility.

Tribological and Micro-Structural Characterization of Ni-Cu-P-W Coatings

2021 ◽  
pp. 209-225
Author(s):  
Bal Mukund Mishra ◽  
Supriyo Roy ◽  
Goutam Kumar Bose
Keyword(s):  
Steel Substrate ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Edx Analysis ◽  
Sem Image ◽  
Annealing Temperatures ◽  
Heat Treated ◽  
Pin On Disc

Ni-Cu-P-W coating was deposited by electroless method on mild steel substrate to study the crystallization and tribological behavior at different annealing temperatures. Energy dispersive x-ray (EDX) analysis, scanning electron microscopy (SEM), x-ray diffraction (XRD), and differential scanning calorimeter (DSC) were used to study the composition, surface morphology, phase behavior, and thermal behavior of the coating, respectively. Tribological study was conducted using Pin-on-Disc tribotester. EDX analysis confirms the presence of Ni, Cu, P, and W in the deposit. SEM image shows the surface is dense, smooth, and without any observable nodule. Some of the samples were heat treated to 300°C, 500°C, and 700°C for 1 hour to observe the crystallographic change by XRD. One sharp crystalline peak of Ni (111) is present in all condition, but the intensity increases rapidly with the heat treatment temperature. The phase transition temperature of this quaternary coating analyzed by DSC was 431.8°C.

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
Dsc Measurements ◽  
Transmission Window

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

Using In Situ High-Energy X-ray Diffraction to Quantify Electrode Behavior of Li-Ion Batteries from Extreme Fast Charging

2021 ◽  
Author(s):  
Partha P. Paul ◽  
Chuntian Cao ◽  
Vivek Thampy ◽  
Hans-Georg Steinrück ◽  
Tanvir R. Tanim ◽  
...  
Keyword(s):  
High Energy ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fast Charging ◽  
Li Ion

Hardening of Selective Laser Melted M2 Steel

2021 ◽  
Author(s):  
Mei Yang ◽  
Yishu Zhang ◽  
Haoxing You ◽  
Richard Smith ◽  
Richard D. Sisson
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
High Hardness ◽  
Steel Part ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Near Net Shape

Abstract Selective laser melting (SLM) is an additive manufacturing technique that can be used to make the near-net-shape metal parts. M2 is a high-speed steel widely used in cutting tools, which is due to its high hardness of this steel. Conventionally, the hardening heat treatment process, including quenching and tempering, is conducted to achieve the high hardness for M2 wrought parts. It was debated if the hardening is needed for additively manufactured M2 parts. In the present work, the M2 steel part is fabricated by SLM. It is found that the hardness of as-fabricated M2 SLM parts is much lower than the hardened M2 wrought parts. The characterization was conducted including X-ray diffraction (XRD), optical microscopy, Scanning Electron Microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) to investigate the microstructure evolution of as-fabricated, quenched, and tempered M2 SLM part. The M2 wrought part was heat-treated simultaneously with the SLM part for comparison. It was found the hardness of M2 SLM part after heat treatment is increased and comparable to the wrought part. Both quenched and tempered M2 SLM and wrought parts have the same microstructure, while the size of the carbides in the wrought part is larger than that in the SLM part.

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