X-RAY INVESTIGATION OF METAL REDUCTION BY MECHANICAL ALLOYING AND SOLID STATE REACTION

1991 ◽  
Vol 05 (20) ◽  
pp. 1355-1359 ◽  
Author(s):  
N. G. DANIELIAN ◽  
S. K. JANAZIAN ◽  
V. V. MELNICHENKO
Keyword(s):  
Solid State ◽  
Mechanical Alloying ◽  
Phase Analysis ◽  
Solid State Reaction ◽  
Amorphous State ◽  
Reduction Reaction ◽  
Metal Reduction ◽  
X Ray ◽  
State Of Metals

X-ray phase analysis was used for studying the reduction reaction of some metals by mechanicals alloying (MA) and solid state reaction. It is shown that it is possible to obtain both amorphous (Mo, W) and crystalline (Pb) metals as a result of such processes. An assumption is set forth that the amorphous state of metals is stabilized at the expense of the various impurities contained in them.

Anomalous solid state reaction between SiC and Pt

1990 ◽  
Vol 5 (3) ◽  
pp. 601-608 ◽  
Author(s):  
T.C. Chou
Keyword(s):  
Solid State ◽  
Diffusion Zone ◽  
Solid State Reaction ◽  
Periodic Structures ◽  
Amorphous State ◽  
Laser Raman Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Raman ◽  
Auger Microscopy

Periodic structures are generated by solid state reaction between platinum (Pt) and silicon carbide (SiC). At temperatures above 900°C, periodic structures consisting of alternating layers of platinum silicides and carbon are produced in the diffusion zone. The composition profile across the diffusion zone and the chemistry of the periodic structures are investigated by scanning electron microscopy (SEM), scanning Auger microscopy (SAM), x-ray diffraction (XRD), and laser Raman microprobe. The formation of the platinum silicides causes an interfacial melting between Pt and SiC. X-ray diffraction indicates that Pt3Si is formed at 900°C, while Pt2Si is formed at 1000 °C. Laser Raman spectroscopy indicates that carbon is in either an amorphous state or a highly ordered graphitic state, depending upon its location from the reaction interface. The mechanism of formation of the periodic structure is discussed in terms of the solubility of carbon in platinum silicide during the solidification process.

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

scholarly journals NOTIZEN. Weitere Verbindungen vom Typ A3NO3: K3NO3 und Rb3NO3 / Further Compounds Typ A3NO3: K3NO3 and Rb3NO3

1980 ◽  
Vol 35 (2) ◽  
pp. 237-238 ◽  
Author(s):  
Martin Jansen
Keyword(s):  
Solid State ◽  
Crystal Structures ◽  
Solid State Reaction ◽  
X Ray

Abstract K3NO3 and RbsNO3 were prepared by solid state reaction of equimolar mixtures of K2O/KNO2 and Rb20/RbN02, respectively. According to X-ray powder photographs their crystal structures are derived from the perovs-kite structure. K3NO3 is isostructural with Na3NO3 (a = 521.7 pm, Z = 1), Rb3NO3 represents a tetragonally distorted variant with a = 770.5, c = 550.8 pm and Z = 2.

Preparation of Ultra–Fine La3NbO7 Powder by Solid State Reaction

2012 ◽  
Vol 512-515 ◽  
pp. 158-161 ◽  
Author(s):  
Ling Dai ◽  
Qiang Xu ◽  
Shi Zhen Zhu ◽  
Ling Liu
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Thermal Barrier ◽  
X Ray Diffraction ◽  
X Ray ◽  
Granular Particle ◽  
Fine Particle Size ◽  
Ultra Fine Particle ◽  
Different Temperatures

As a new candidate material for the ceramic layer in thermal barrier coatings (TBCs) system, La3NbO7 was synthesized with La2O3 powder and Nb2O5 powder by solid state reaction. The stating powders with a mole ratio of La to Nb of 3:1 were mixed and then the mixture was calcined under the different temperatures(800°C, 1000°C, 1200°C) and dwell times(2h, 6h, 10h). The phase structure of the powder was observed by X–ray diffraction(XRD), and the microstructure of the sample was observed by scanning electron microscope(SEM). The effect of calcination temperature and dwell Time on the phase formation were examined. The results indicate that the La3NbO7 powder with single phase can be synthesized successfully at 1200°C for 10h in air, and the La3NbOsub>7 powders synthesized have an ultra-fine particle size of 0.5˜1µm with a granular particle shape. With the temperature increasing, LaNbO4/sub> was synthesized firstly and then La3NbO7 was synthesized with a mole ratio of La2O3 to LaNbO4 of 1:1.

scholarly journals Thermal solid-state Z/E isomerization of 2-alkylidene-4-oxothiazolidines: Effects of non-covalent interactions

2011 ◽  
Vol 76 (3) ◽  
pp. 317-328 ◽  
Author(s):  
Zdravko Dzambaski ◽  
Milovan Stojanovic ◽  
Marija Baranac-Stojanovic ◽  
Dragica Minic ◽  
Rade Markovic
Keyword(s):  
Solid State ◽  
1H Nmr Spectroscopy ◽  
Amorphous State ◽  
Intramolecular Hydrogen Bonding ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Configurational Isomerization ◽  
Non Covalent Interactions ◽  
Intramolecular Hydrogen ◽  
Covalent Interactions

Configurational isomerization of stereo-defined 5-substituted and unsubstituted 2-alkylidene-4-oxothiazolidines 1 in the solid state, giving the Z/E mixtures in various ratios, was investigated by 1H-NMR spectroscopy, X-ray powder crystallography and differential scanning calorimetry (DSC). The Z/E composition can be rationalized in terms of non-covalent interactions, involving intermolecular and intramolecular hydrogen bonding and directional non-bonded 1,5-type S...O interactions. X-Ray powder crystallography, using selected crystalline (Z)-4- oxothiazolidine substrates, revealed transformation to the amorphous state during the irreversible Z ? E process. A correlation between previous results on the Z/E isomerization in solution and now in the solid state was established.

SYNTHESIS, MORPHOLOGY AND STRUCTURAL PROPERTIES OF (GD,ND)SR2RUCU2O8 SAMPLES

2003 ◽  
Vol 17 (04n06) ◽  
pp. 899-904 ◽  
Author(s):  
A. VECCHIONE ◽  
M. GOMBOS ◽  
C. TEDESCO ◽  
A. IMMIRZI ◽  
L. MARCHESE ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
X Ray ◽  
Structure And Morphology ◽  
Polycrystalline Powder ◽  
Scanning Electron

NdSr 2 RuCu 2 O x material has been prepared as polycrystalline powder by solid state reaction. The compound has been investigated by synchrotron x-ray powder diffraction and scanning electron microscopy. The experimental results show that the average crystal structure is a disordered cubic perovskite with Nd and Sr cations occupying the same site and the same substitution is found for Cu and Ru atoms. A comparison between the crystal structure and morphology of this compound and the superconducting tetragonal GdSr 2 RuCu 2 O 8 is also discussed.

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