X-ray study of the liquid and solid phases of the alkali metals inKC24- andRbC24-intercalated graphite single crystals

1990 ◽  
Vol 42 (1) ◽  
pp. 725-742 ◽  
Author(s):  
F. Rousseaux ◽  
R. Moret ◽  
D. Guerard ◽  
P. Lagrange
Keyword(s):  
Single Crystals ◽  
Alkali Metals ◽  
X Ray ◽  
Intercalated Graphite ◽  
Solid Phases ◽  
Liquid And Solid Phases

Synthesis and Characterization of Large Single Crystals of Silicon and Germanium Clathrate-II Compounds and a New Tin Compound with Clathrate Layers

2000 ◽  
Vol 626 ◽  
Author(s):  
Svilen Bobev ◽  
Slavi C. Sevov
Keyword(s):  
Alkali Metal ◽  
Single Crystals ◽  
Alkali Metals ◽  
Measured Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Alkali ◽  
Pauli Paramagnetism ◽  
Silicon And Germanium

ABSTRACTWe have synthesized large single crystals of clathrate-II compounds with frameworks of silicon and germanium by employing mixed alkali metal countercations. The combinations of alkali metals are rationally selected in order to fit the different cages of the clathrate-II structure. This approach leads to the following stoichiometric and fully “stuffed” compounds: Cs8Na16Si136, Cs8Na16Ge136, Rb8Na16Si136 and Rb8Na16Ge136. The structures and the corresponding Si-Si and Ge-Ge distances are elucidated and established with high accuracy from extensive single crystal X-ray diffraction work. The compounds are stoichiometric, metallic, and are very stable at a variety of extreme conditions such as heat, concentrated acids, hydrothermal treatment etc. No evidence was found for vacancies in the silicon and germanium networks or partial occupancies of the alkali metal sites. The stoichiometry of these fully “stuffed” clathrates is consistent with the measured temperature independent Pauli paramagnetism, supported also by the conductivity measurements on single crystals and thermopower measurements on pellets. A new compound with novel clathrate-like structure forms when small and large cations are combined with tin. The new materials, A6Na18Sn46 (A = K, Rb, Cs), are made of clathrate layers and the interlayer space filled with Sn4-tetrahedra and alkali-metal cations. Its formula can be rationalized as A6Na6Sn34 + 3·Na4Sn4 (one clathrate layer and three tin tetrahedra). The compound is stable in air and is being currently tested at other conditions. Detailed measurements of its transport properties are under way.

scholarly journals Methods to Determine Characteristics of AOD-Converter Decarburization-Slags

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 308
Author(s):  
Patrik Ternstedt ◽  
Gunilla Runnsjö ◽  
Anders Tilliander ◽  
Jesper Janis ◽  
Nils Å. I. Andersson ◽  
...  
Keyword(s):  
Measured Data ◽  
Limited Information ◽  
X Ray ◽  
Solid Phases ◽  
Argon Oxygen Decarburization ◽  
The Difference ◽  
Industrial Samples ◽  
Liquid And Solid Phases ◽  
Aod Slag ◽  
Good Agreement

Argon Oxygen Decarburization (AOD) converter slags are known to consist of both liquid and solid phases, but limited information on the slag characteristics has been published in the open literature. Therefore, a new methodology to study the characteristics of slag samples taken from the AOD converter process during production was developed based on petrography. The results show that the preparations of the slag samples using the borax method are suitable to use when determining the chemical composition of AOD slag samples using the X-ray fluorescence (XRF) method. The results also showed that both the light optical microscopy (LOM) method and a method combining scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) can be used to characterize the slag samples and that the correlation between the methods was found to be good. This means that it is possible to use the faster LOM method instead of the more complicated SEM-EDS method to characterize AOD slag samples. Finally, the results show that the difference between calculated values based on stoichiometry and measured data for Ca and Cr in AOD slags are 11.7 mass% and 11.3 mass%, respectively. This is considered to be a good agreement for industrial samples.

scholarly journals PHASE EQUILIBRIA IN THE NaCl–CaCl2–CaO SYSTEM

2021 ◽  
Vol 87 (2) ◽  
pp. 77-86
Author(s):  
Anatoliy Omelchuk ◽  
Igor Skryptun ◽  
Nikolay Zakharchenko ◽  
Olha Bosenko ◽  
Ruslan Savchuk ◽  
...  
Keyword(s):  
Ternary System ◽  
Phase Equilibria ◽  
Metal Oxides ◽  
Calcium Oxide ◽  
Refractory Metal ◽  
Polythermal Section ◽  
X Ray ◽  
Polythermal Sections ◽  
Solid Phases ◽  
Liquid And Solid Phases

The phase equilibria of the ternary system CaCl2 – NaCl – CaO in the area which enriched of calcium and sodium chloride were investigated by the methods of differential-thermal analysis and powder X-ray phase analysis. In the systems were determined the equilibrium concentration of calcium oxide and the composition of the phases, which at the same time exist in an equilibrium state at different temperatures. The surfaces of liquidus and solidus were established, the compositions of the sections of the ternary system CaCl2–NaCl–CaO were defined, which recommended for electrochemical reduction of refractory metal oxides (titanium, zirconium and other), which allow electrolysis in the temperature range from 550 to 1000 °С. Five polythermal sections of the NaCl – CaCl2 – CaO ternary system were studied. For each polythermal section the regions of existence of the liquid and solid phases were established. For each polythermal section state diagrams were constructed. Used X-Ray phase analyses it was established the compositions of liquid and solid phases for each polythermal sections. The phases of which the system consists were determined. At a constant ratio of components [NaCl]:[CaCl2] = 1.06 (mol.) in the melts of the ternary system CaCl2 – NaCl – CaO, the equilibrium content of calcium oxide reaches 12.0 mol.%, while their crystallization temperature does not exceed 550 °C. This allows us to recommend mixtures of this composition for electrochemical reduction of refractory metal oxides in a wide range of temperatures (from 550 to 1000 °C) with a high content of both calcium and sodium chlorides (not less than 40 mol.%) and oxide. calcium (up to 12.0 mol.%). The eutectic of this ternary system has a melting point of 480 ° C and corresponds to he composition (mol.%): CaCl2 (45.8) – NaCl (47.0) – CaO (7.2).

Structural studies of N-(2′-substituted phenyl)-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboximides by X-ray diffraction and NMR spectroscopy—proofs for CH/π interactions in liquid and solid phases

2003 ◽  
Vol 27 (7) ◽  
pp. 1095-1101 ◽  
Author(s):  
Gisbert Grossmann ◽  
Marek J. Potrzebowski ◽  
Sebastian Olejniczak ◽  
Natasza E. Ziółkowska ◽  
Grzegorz D. Bujacz ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Π Interactions ◽  
Solid Phases ◽  
Liquid And Solid Phases

Zone-axis ALCHEMI for the rapid assessment of site occupancies in garnets

1986 ◽  
Vol 44 ◽  
pp. 706-707
Author(s):  
M.T. Otten ◽  
P.R. Buseck
Keyword(s):  
Single Crystals ◽  
Rapid Assessment ◽  
Site Occupancy ◽  
Zone Axis ◽  
Synthetic Compounds ◽  
X Ray ◽  
Large Group ◽  
Crystallographic Planes

ALCHEMI (Atom Location by CHannelling-Enhanced Microanalysis) is a TEM technique for determining site occupancies in single crystals. The method uses the channelling of incident electrons along specific crystallographic planes. This channelling results in enhanced x-ray emission from the atoms on those planes, thereby providing the required site-occupancy information. ALCHEMI has been applied with success to spinel, olivine and feldspar. For the garnets, which form a large group of important minerals and synthetic compounds, the channelling effect is weaker, and significant results are more difficult to obtain. It was found, however, that the channelling effect is pronounced for low-index zone-axis orientations, yielding a method for assessing site occupancies that is rapid and easy to perform.

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