Kinetic Study on the Formation of the Aragonite-Like Phase Ba(CuOx)1-Y(CO3)y

1995 ◽  
Vol 398 ◽  
Author(s):  
A. Tomasi ◽  
E. Galvanetto ◽  
F.C. Matacotta ◽  
P. Nozar ◽  
P. Scardi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
High Resolution Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Techniques ◽  
Formation Kinetics ◽  
Resolution Electron ◽  
Thermal Analysis Techniques ◽  
Kinetics Of

ABSTRACTA systematic study on phase formation and stabilisation in the Ba-Cu-C-O system in the temperature range 20-500°C, under various atmospheres, by traditional thermal analysis techniques, high temperature X-ray diffraction and high resolution electron microscopy, has permitted to identify and characterise the formation kinetics of a new copper containing phase isomorphic to γ-BaCO3.

Laser Ablation Synthesis of Ceramic Powders

1990 ◽  
Vol 201 ◽  
Author(s):  
W. G. Fahrenholtz ◽  
S. R. Foltyn ◽  
K. C. Ott ◽  
M. Chadwick ◽  
D. M. Smith
Keyword(s):  
Thermal Analysis ◽  
Laser Ablation ◽  
Aluminum Oxide ◽  
Fine Powder ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
X Ray ◽  
Analysis Techniques ◽  
Aluminum Metal ◽  
Thermal Analysis Techniques

AbstractA pulsed excimer laser was used to ablate aluminum metal into an oxygen-containing atmosphere. The resulting fine powder was collected on a 0.1 μm filter and analyzed to determine structure and composition. Using a combination of TEM, EELS, and thermal analysis techniques, the product was found to be amorphous aluminum oxide, Al2O3. The morphology of the powders was investigated using SEM, TEM, and surface area measurements. The resulting powder was crystallized and examined by x-ray diffraction.

Electron optical studies of the formation of vanadium pentoxide catalyst

1987 ◽  
Vol 45 ◽  
pp. 354-355
Author(s):  
A. Legrouri
Keyword(s):  
Electron Microscopy ◽  
Vanadium Pentoxide ◽  
High Resolution Electron Microscopy ◽  
X Ray Diffraction ◽  
Optical Studies ◽  
X Ray ◽  
Physicochemical Changes ◽  
Structural Correlation ◽  
Resolution Electron ◽  
Xrd Techniques

The oxides of vanadium, especially vanadium pentoxide, have been extensively studied because of their interesting physical properties particularly in catalysis. Vanadium pentoxide is generally used in the oxidation and ammoxidation of hydrocarbons.This catalyst has been prepared via the thermal decomposition of ammonium metavanadate (AMV) in air. Thermogravimetric analysis (TGA), infrared spectroscopy (IRS) and x-ray diffraction (XRD) techniques together with high resolution electron microscopy (HREM) and scanning electron microscopy (SEM) have enabled us to elucidate the physicochemical changes occurring during the decomposition process.According to TGA results, the decomposition of AMV commences at 150°C and is complete by 320°C leading to vanadium pentoxide by loss of ammonia and water with the formation of two intermediate compounds, namely at 190°C, ammonium bivanadate: (NH4)2V4 O11, and at 230°C, ammonium hexavanadate AHV: (NH4)2V6O16 . Samples for structural correlation studies were prepared by heating AMV in a stream of air for 2 hours at selected temperatures of 140, 190, 230, 320 and 400°C.

High Resolution Electron Microscopy of a Novel Zeolite

1997 ◽  
Vol 3 (S2) ◽  
pp. 441-442
Author(s):  
P.A. Crozier ◽  
I.Y. Chan ◽  
C.Y. Chen ◽  
L.W. Finger ◽  
R.C. Medrud ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
X Ray Diffraction ◽  
High Adsorption ◽  
Structural Units ◽  
X Ray ◽  
Resolution Electron ◽  
Crystal Structural

Low-dose high resolution electron microscopy (HREM) is a useful technique for elucidating the structure of zeolites. In recent years a number of zeolite structures have been solved using combinations of different characterization techniques including adsorption measurements, powder x-ray diffraction and low-dose high resolution electron microscopy (for example see ref. 2). We have used these techniques to study the structure of a novel zeolite material. However, great care must be exercised when interpreting data from these techniques in terms of crystal structural units. In this particular case, the structure was recently determined using single crystal x-ray diffraction and showed some surprises.Details of the synthesis of this zeolite are given elsewhere. The high adsorption capacity suggested that this zeolite possessed two interpenetrating channels (either a 10 and a 12 ring or two 12 ring channels). X-ray powder diffraction showed the material to be monoclinic with a= 18.5Å, b= 13.4 Å, c= 7.6 Å β = 101.5°).

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