98/00110 Changes of the graphite crystallite sizes of coal-derived materials as a result of heat treatment to 2500°C

1998 ◽  
Vol 39 (1) ◽  
pp. 10
Keyword(s):  
Heat Treatment ◽  
Graphite Crystallite ◽  
Crystallite Sizes

Study of the Surface Morphology and the Microstructure of PAN-Based Carbon Fibers

2011 ◽  
Vol 239-242 ◽  
pp. 1279-1282
Author(s):  
Xue Jun Zhang ◽  
Zan Han ◽  
Yan Hong Tian ◽  
Yan Feng Yang
Keyword(s):  
Electron Microscopy ◽  
Carbon Fibers ◽  
Interlayer Spacing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Graphite Crystallite ◽  
Crystallite Sizes ◽  
Degree Of Graphitization ◽  
Better Than

The microstructure of two kinds of self-made PAN-based high-modulus carbon fibers (HMCF-1, HMCF-2) was studied by scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM), and was compared with that of T800 and M55J. The correlation of XRD and HRTEM in terms of graphite crystallite sizes and interlayer spacing of graphite layer was also investigated. The results show that the diameters of T800, HMCF-1 and HMCF-2 are almost the same (~5.20μm) and all of them are lager than that of M55J (~4.86μm). The crystal sizes and the degree of graphitization are in the order of HMCF-2>HMCF-1>M55J>T800, while the regularity of the lattice fringes of HMCF-2 is better than those of others.

scholarly journals Твердофазные реакции и фазовые превращения в наноразмерной пленочной структуре висмут/селен

2018 ◽  
Vol 52 (8) ◽  
pp. 823
Author(s):  
В.Я. Когай ◽  
Г.М. Михеев
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Phase Transformations ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Film Structure ◽  
Phase Synthesis ◽  
Crystallite Sizes ◽  
Solid Phase Reactions ◽  
First Time

AbstractExperimental results of a study concerned with solid-phase reactions and phase transformations in a Bi/Se nanoscale film structure under heat treatment in vacuum are presented. Nanocrystalline Bi2Se3, BiSe, and Bi_4Se_3 films are obtained for the first time by solid-phase synthesis at various ratios between the Bi and Se layer thicknesses. The phase-transformation temperatures at which Se, BiSe, and Bi4Se3 crystalline phases are formed are determined. The average crystallite sizes in the Bi_2Se_3, BiSe, and Bi_4Se_3 films are found to be 21, 23, and 33 nm, respectively.

Effect of Structure on the Mechanical Properties of PAN-Based Carbon Fibers during Graphitization

2011 ◽  
Vol 686 ◽  
pp. 770-777 ◽  
Author(s):  
Hao Xiao ◽  
Yong Gen Lu ◽  
Xian Ying Qin ◽  
Ya Wen
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fiber Surface ◽  
Total Porosity ◽  
Interlayer Spacing ◽  
Temperature Treatment ◽  
Treatment Temperature ◽  
High Temperature Treatment ◽  
X Ray Diffraction ◽  
Crystallite Sizes

An investigation was conducted to determine the influence of high temperature treatment from 1600°C to 2800°C under stretching stress of 10MPa on PAN-based carbon fiber structure and physical properties. The tensile strength of fibers decreased from 4.5GPa to 2.97GPa with increasing treatment temperature up to 2800°C，while the modulus of fibers increased from 230GPa to 375GPa The texture in the longitudinal surface of fibers through heat treatment was characterized using a scanning electron microscopy. The contours of fiber surface became accidented with gaps becoming deeper as temperature increased. It has been observed that both the crystallite sizes (La, Lc) and the degree of preferred orientation increasd, while the crystallite interlayer spacing (d002) decreased by X-ray diffraction analysis with increasing heat-treatment temperature. The total porosity of fibers decreased from 21.01% to 15.09% and while the density of fibers increased from 1.720g/cm-3to1.886 g/cm-3with increasing heat-treatment. In addition, the relationship between mechanical properties and structure of variants was also explored in detail.

Evolution of crystalline zirconia structure in heat-treated ceria stabilized zirconia gels

1991 ◽  
Vol 6 (12) ◽  
pp. 2688-2693 ◽  
Author(s):  
V.S. Nagarajan ◽  
K.J. Rao
Keyword(s):  
Heat Treatment ◽  
Temperature Region ◽  
Diffusion Barriers ◽  
Line Broadening ◽  
Stabilized Zirconia ◽  
Major Phase ◽  
X Ray ◽  
Stable Regime ◽  
Heat Treated ◽  
Crystallite Sizes

Transformation characteristics of CeO2 stabilized ZrO2 gels have been studied during heating in the temperature region 1273–1473 K. The nature of the major phase present changes drastically in this temperature region. The crystallite sizes of tetragonal and monoclinic ZrO2 crystallites have been calculated by x-ray line broadening. The change in the nature of the major phase observed during heat treatment seems to be related to the presence of a barrier for transformation from a metastable to a stable regime, which in turn appears to be related to the diffusion barriers of Ce4+ in ZrO2.

Correlation between graphite crystallite distribution morphology and the mechanical properties of carbon fiber during heat treatment

2011 ◽  
Vol 65 (23-24) ◽  
pp. 3444-3446 ◽  
Author(s):  
Aijun Gao ◽  
Chun Zhao ◽  
Sha Luo ◽  
Yuanjian Tong ◽  
Lianghua Xu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Carbon Fiber ◽  
Graphite Crystallite

Annealing Temperature Effects in Co-Precipitated CoFe2O4 Nanoparticles Using Bengawan Solo River Fine Sediment

2020 ◽  
Vol 855 ◽  
pp. 64-69
Author(s):  
Ahmad Thabib Mubarok ◽  
Hendri Widiyandari ◽  
Utari ◽  
Budi Purnama
Keyword(s):  
Heat Treatment ◽  
Temperature Effects ◽  
Rate Ratio ◽  
Annealing Temperature ◽  
Raw Materials ◽  
Reduction Rate ◽  
Fine Sediment ◽  
Fine Sediments ◽  
Maximum Reduction ◽  
Crystallite Sizes

In this study, the synthesis of CoFe2O4 by using the fine sediment of the Bengawan Solo River, Trucuk District, Bodjonegoro Regency as raw materials with the coprecipitation method has been successfully carried out. The fine sediment is used as a source of Fe cation in the synthesis of CoFe2O4. The XRD confirmation results showed that CoFe2O4 is formed at an annealing temperature of 800° C with crystallite sizes ranging from 34.88 to 38.05 nm. Thus, the VSM characterization showed that the magnetic properties of the CoFe2O4 nanoparticles depend on the heat treatment of the fine sediments as ore materials. Finally, the obtained CoFe2O4 samples can be used as photocatalysts with a maximum reduction rate ratio of 83%.

Annealing Effect on Microstructure and Coercivity of YCo5 Nanoparticles Obtained by Mechanical Milling

2009 ◽  
Vol 68 ◽  
pp. 122-126
Author(s):  
José Trinidad Elizalde Galindo ◽  
Reiko Sato Turtelli ◽  
Roland Grössinger ◽  
José Andrés Matutes-Aquino
Keyword(s):  
Heat Treatment ◽  
Exchange Interaction ◽  
Mechanical Milling ◽  
Room Temperature ◽  
Hysteresis Loops ◽  
Annealing Effect ◽  
Subsequent Heat Treatment ◽  
High Coercivity ◽  
Crystallite Sizes

Nanocrystalline YCo5 powders with high coercivity were prepared by mechanical milling and subsequent heat treatment at 820 °C for different annealing times, ta = 2.5, 3.0, 3.5 and 4.5 min, obtaining average crystallite sizes of <D>  17, 19, 32 and 39 nm., respectively. The coercivity values were determined from the hysteresis loops measured at maxima fields of Hm = 5 and 20 T. The highest coercivity was obtained for the sample exhibiting <D>  19 nm, where at room temperature and Hm = 5 T, the coercivity value is of 9.0 kOe. At 77 K and Hm = 5 T, the coercivity increase to 11.8 kOe and for Hm = 20 T, a higher value such as 13.1 kOe was found. The Ms/Mr ratio is enhanced to 0.62 indicating the occurrence of exchange interaction among nanocrystalline magnets.

XRD and EDXRF Analysis of Anatase Nano-TiO2 Synthesized from Mineral Precursors

2012 ◽  
Vol 620 ◽  
pp. 179-185 ◽  
Author(s):  
E.M. Mahdi ◽  
Mohd Hamdi Abdul Shukor ◽  
Meor Sulaiman Meor Yusoff ◽  
Paulus Wilfred
Keyword(s):  
Heat Treatment ◽  
Chemical Composition ◽  
Anatase Phase ◽  
Processing Parameters ◽  
High Quality ◽  
Relative Crystallinity ◽  
Edxrf Analysis ◽  
Crystallite Sizes ◽  
Metallic Impurities

This work details the characterization of anatase nanoTiO2particles synthesized from Malaysian mineral precursors using the XRD and EDXRF. The properties that were analyzed were its crystallite sizes, relative crystallinity, phases, and chemical composition. It was determined that the crystallite size was quite small (15.6 nm), although the crystallinity of the sample is relatively low. The anatase phase seems to be dominant (100%), although in some cases when the processing parameters were changed or heat treatment were conducted, the existence of rutile is detected. The chemical composition showed that TiO2is the majority compound in the sample (~96%), although some metallic and non-metallic impurities are present (Zr, Nb, and S). It is concluded that Malaysian mineral precursors are capable of producing relatively high quality nanoTiO2.

The Precipitation of Si in AlCuSi Thin Films

1973 ◽  
Vol 31 ◽  
pp. 34-35 ◽  
Author(s):  
R. M. Anderson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Heat Treatment ◽  
Solid Solution ◽  
Integrated Circuit ◽  
Copper Film ◽  
Solution Concentration ◽  
X Ray ◽  
Silicon Thin Films ◽  
Before And After

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.

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