scholarly journals Sintering Mechanism of silicon from K2SiF6-Al

2020 ◽  
Vol 165 ◽  
pp. 03045
Author(s):  
Zhaoke Pan ◽  
Jinhua Wang ◽  
Guizhai Zhang
Keyword(s):  
Diffraction Analysis ◽  
Formation Process ◽  
The Other ◽  
Reaction Process ◽  
X Ray Diffraction ◽  
Solid Reaction ◽  
Reaction Stage ◽  
X Ray ◽  
Liquid Reaction ◽  
Solid Liquid

In order to clarify the reaction process of Si phase, Differential Scanning Calorimeter (DSC), as the main measurement, was used to prepare Si samples and monitor the sintering reaction process. Combined with X-ray diffraction analysis, the formation process of Si phase was summarized. The reaction between K2SiF6 and Al powders occurred at 580°C, but not completed until 660°C. The whole formation process of Si includes two different stages: One is the solid–solid reaction stage, the other is the solid–liquid reaction stage.

Wet-Purification of a Sodium-Based Bentonite

2013 ◽  
Vol 743-744 ◽  
pp. 692-696
Author(s):  
Shui Lin Zheng ◽  
Yang Yang Huai ◽  
Zhen Wei Li ◽  
Hao Ran Cui ◽  
Zhi Ming Sun
Keyword(s):  
Methylene Blue ◽  
Diffraction Analysis ◽  
Purification Process ◽  
X Ray Diffraction ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Bentonite mainly consists of montmorillonite, but is always associated with other impure minerals. In order to increase the montmorillonite content in raw bentonite from Xinjiang, this paper adopts wet-purification process which integrates the scrubbing process with streamlined centrifugalization. The optimum experiment condition is solid - liquid ratio (wv) 130, macerating time 20h, scrubbing time 10min, centrifugation time 13min, centrifugation velocity 1260r/min, ZHL dosage 0.4% and ZHC dosage 0.4%. According to the amount of methylene blue absorption raising from 64.5mmol/100g to 110mmol/100g and X-ray diffraction analysis, the montmorillonite content raises from 48% to 82%.

scholarly journals Caracterização metalúrgica de ligas de Ni-Cr para metalocerimica

2021 ◽  
Vol 40 (1) ◽  
pp. 57-59
Author(s):  
Carlos Ariel Samudio Perez ◽  
Cezar Augusto Garbin
Keyword(s):  
Solid Solution ◽  
Diffraction Analysis ◽  
The Other ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tests ◽  
Density Values ◽  
Cubic Structure ◽  
Hardness Values

Alternative Ni-Cr alloys applied in dentistry of two commercial brands for ceramometal restoration were evaluated. The alloys were analyzed in the commercial and after casting conditions using experimental techniques of metallography, X-ray diffraction, superficial hardness and density. The metalografics and X-ray diffraction analysis showed that, the alloys microstructure is marked with the presence of a solid solution having an ordered face- centred cubic structure, Ni-rich austenitic (y phase) matrix, and with fine precipitates particles of secondary phases. The Vicker hardness tests showed a decrease in hardness values of the studied alloys aer casting. The alloys density values, on the other hand, did not manifest changes.

Solid-Liquid Reaction for Synthesis of Rodlike Submicron Oxalate and the Thermolysis to Nanostrings of Co3O4 Nanobeads

2011 ◽  
Vol 233-235 ◽  
pp. 260-263
Author(s):  
Xian Da He ◽  
Hong Qi Ye ◽  
Qin Kuai ◽  
Kai Hua Xu ◽  
Hong Tao Han
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Liquid Reaction ◽  
Average Aspect Ratio ◽  
Cobalt Oxalate ◽  
Solid Liquid ◽  
Scanning Electron

A novel solid-liquid reaction route has been developed to synthesize rodlike submicron cobalt oxalate via dissolution of cobalt powders by oxalic acid. The rod diameter and length of the oxalate particles were found to be remarkably altered by using HCl or HNO3as additive. With HCl as additive rice-shaped particles were generated while with HNO3slender needlelike particles were created with an average aspect ratio up to 42. Furthermore, strings of Co3O4nanobeads were obtained by calcination of the slender precursor particles in air. The CoC2O4·2H2O submicron rods and Co3O4nanobeads were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TG), and X-ray diffraction (XRD).

scholarly journals Solid state interactions in the systems CaO(CaCO3)-Fe2O3 and CuFe2O4-CaO

2005 ◽  
Vol 41 (1) ◽  
pp. 67-77 ◽  
Author(s):  
B.S. Boyanov
Keyword(s):  
Sulfuric Acid ◽  
Solid State ◽  
Acid Solution ◽  
Diffraction Analysis ◽  
Sulfuric Acid Solution ◽  
Formation Process ◽  
X Ray Diffraction ◽  
Exchange Reactions ◽  
X Ray ◽  
Ferrite Formation

The solid state interactions in the systems CaO(CaCO3)-Fe2O3 and CuFe2O4-CaO have been studied using X-ray diffraction analysis. The influence of the temperature on the ferrite formation process has been investigated in the range of 900-1200 oC and duration up to 360 min. It has been shown that a mixture of ferrites forms at 1000 oC and interaction of 240 min. The exchange reactions in the systems CuFe2O4-CaO and Cu0.5Zn0.5Fe2O4-CaO have been studied, too. It has been established that Ca2+ ions exchange Cu2+ and Zn2 partially and the solubility of copper and zinc in a 7 % sulfuric acid solution increases 10-15 times.

Evidence for hydrothermal growth of diamond in the C–H–O and C–H–O halogen system

1996 ◽  
Vol 11 (5) ◽  
pp. 1164-1168 ◽  
Author(s):  
Rustum Roy ◽  
D. Ravichandran ◽  
P. Ravindranathan ◽  
A. Badzian
Keyword(s):  
Raman Spectrum ◽  
Solid State ◽  
The Other ◽  
Strong Increase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Liquid Precursors ◽  
Organic Solid ◽  
Fine Diamond ◽  
Solid Liquid

Powder x-ray diffraction (XRD) and Raman evidence are presented for the formation of crystalline diamond in the “hydrothermal” pressure-temperature regime 1–5 kbars, <1000 °C. Two different methods appear to enable diamond to nucleate and grow. One—a Low Pressure Solid-State Source (LPSSS) route—utilizes special solid precursors, especially low temperature glassy carbon (GC-500), with very fine diamond seeds in sealed gold capsules with H2O at, say, 800 °C and 1 kbar. The other includes pyrolysis of highly selected organic solid/liquid precursors (halogenated aliphatics such as iodoform) onto similar diamond seeds. In all the cases, powder x-ray diffraction evidence shows a marked increase of the diamond XRD peaks, likewise the Raman spectrum shows a strong increase of the 1331 cm−1 line. However, the crystals apparently are too small to be seen in the SEM. TEM diffraction data, on the other hand, seem to lend support to the possibility of all the grown diamonds being very small.

Reactions of PO(NCS)3 with 4-Hydroxy-1,3-dioxanes. Crystal Structure of rel-(2S,4R,5S,6S)-2,6-Diethyl-5-methyl-4-(N'-benzylthioureido)-1,3-dioxane

1992 ◽  
Vol 57 (6) ◽  
pp. 1299-1313 ◽  
Author(s):  
Juraj Bernát ◽  
Ladislav Kniežo ◽  
Gabriela Birošová ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Analysis ◽  
Nmr Spectra ◽  
Crystalline Form ◽  
The Other ◽  
Axial Position ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Alkyl Groups

Substituted 4-hydroxy-1,3-dioxanes II react rapidly with PO(NCS)3 to give 4-isothiocyanato-1,3-dioxanes III. The 1H NMR spectra showed that in the isothiocyanate IIIa the predominant stereoisomer has its NCS group in axial position. The addition of benzylamine to the isothiocyanates IIIa and IIIb gave uniform thioureas IVa and IVb with equatorial alkyl groups at 2 and 6 positions and axial thioureido group at 4 position. On the other hand, the isothiocyanate IIIc reacts with benzylamine to give a mixture of three stereoisomeric thioureas V,VI, and VIII. The structure of VI was proved by means of X-ray diffraction analysis; in crystalline form the molecules of VI are present as H-bonded dimers (N-H...O).

Water Assisted Conversion of ZnO from Metallic Zinc Particles

2013 ◽  
Vol 538 ◽  
pp. 38-41
Author(s):  
Qing Lan Ma ◽  
Rui Xiong ◽  
Bao Gai Zhai ◽  
Yuan Ming Huang
Keyword(s):  
Room Temperature ◽  
Green Emission ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Xrd Pattern ◽  
X Ray ◽  
Uv Emission ◽  
Liquid Reaction ◽  
Sem Study ◽  
Solid Liquid

Zinc oxide (ZnO) was synthesized by solid-liquid reaction of raw Zn particles in water. The synthesized ZnO were characterized with X-ray diffraction (XRD), scanning electronic microscopy (SEM) and photoluminescence (PL) spectrophotometer. The XRD pattern confirmed that the formation of ZnO with wurtzite structure and ZnOOH crystals. The SEM study clearly exhibited a honeycomb-shaped structure of the Zn/ZnO/ZnOOH composites. Room-temperature PL spectra have been observed a very weak UV emission at 376 nm and a very strong yellow-green emission at 538 nm. Furthermore, a possible mechanism of the water-assisted conversion of ZnO from metallic Zn particles was discussed.

Self-Assembly of 1,1'-Biphenyl-2,2',6,6'-tetracarboxamides. Effect of Substitution at the Amidic Nitrogen

2001 ◽  
Vol 66 (6) ◽  
pp. 947-958 ◽  
Author(s):  
Petr Holý ◽  
Jaroslav Podlaha ◽  
Ivana Císařová ◽  
Jiří Závada
Keyword(s):  
Hydrogen Bonds ◽  
Diffraction Analysis ◽  
Self Assembly ◽  
The Other ◽  
Amide Hydrogen ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Assembling ◽  
Alkyl Substitution ◽  
2D Network

Self-assembly of three 1,1'-biphenyl-2,2',6,6'-tetracarboxamides 2a-2c differing each from the other by substitution at the amidic nitrogens (R = H, ethyl and 1-(R)-phenylethyl, respectively) was investigated by single crystal X-ray diffraction analysis. It was found that the unsubstituted tetracarboxamide 2a gives rise to infinite hydrogen-bonded 2D network composed from chiral cyclotetrameric squares (D4 symmetry). Such self-assembling pattern is suppressed by alkyl substitution in 2b and 2c, which disfavours formation of intermolecular amide-amide hydrogen bonds.

A Dinuclear Adduct of bis(di-sec-butyl dithiophosphato) Cadmium(II) Built around the Hexamethylenetetramine Cage as Coordination Center

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Liviu Bolundut ◽  
Ionel Haiduc ◽  
Mary F. Mahon ◽  
Kieran C. Molloy
Keyword(s):  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
The Other ◽  
Dinuclear Complex ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ir And Nmr Spectroscopy ◽  
Coordination Center ◽  
Chelating Ligand ◽  
Ft Ir

Bis(di-sec-butyldithiophosphato)cadmium(II) forms a 2:1 adduct with hexamethylenetetramine (urotropine), which was characterized by FT-IR and NMR spectroscopy. The compound is a dinuclear complex with the cadmium atoms coordinated at two nitrogen atoms of hexamethylenetetramine cage which is the actual coordination center. The X-ray diffraction analysis of the complex reveals a distorted square pyramidal coordination of the five-coordinate cadmium atoms. At each cadmium, one dithiophosphato group behaves as slightly anisobidentate whereas the other one is an isobidentate chelating ligand.

Sign in / Sign up

Export Citation Format

Share Document