Study of NH4EuF4 in solid state reaction Eu2O3–NH4F. Thermal analyses, calorimetry, and decomposition kinetics

1977 ◽  
Vol 55 (14) ◽  
pp. 2628-2630 ◽  
Author(s):  
Krishnan Rajeshwar ◽  
Etalo A. Secco
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Solid State Reaction ◽  
Thermal Analyses ◽  
Decomposition Kinetics ◽  
X Ray ◽  
Kinetics Of Thermal Decomposition ◽  
Heat Of Decomposition ◽  
Kinetics Of

The solid state reaction Eu2O3–NH4F leading to the formation of NH4EuF4 was studied by thermal analyses and X-ray diffraction.The heat of decomposition of NH4EuF4 and the kinetics of thermal decomposition of NH4EuF4 are reported.

Thermal Decomposition Kinetics of Ammonium Aluminum Carbonate Hydroxide

2008 ◽  
Vol 368-372 ◽  
pp. 1577-1579
Author(s):  
Hai Jun Zhang ◽  
En Xia Xiu ◽  
Xiu Juan Wang ◽  
Quan Li Jia ◽  
Hong Wei Sun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Preexponential Factor ◽  
Decomposition Kinetics ◽  
Algebraic Expression ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbonate Hydroxide ◽  
Kinetics Of ◽  
Scanning Electron

The thermal decomposition of ammonium aluminum carbonate hydroxide was studied under non-isothermal conditions in air. The decomposition kinetics were evaluated from data of TG-DTA by means of the Kissinger equation and the Coats-Redfern equation. The values of the activation energy E, the preexponential factor A and the algebraic expression of integral G(α) functions of the thermal decomposition were calculated. The ammonium aluminum carbonate hydroxide (AACH) was characterized by X-ray diffraction, differential thermal analysis and thermogravimetric and field emission scanning electron microscopy.

X-ray powder diffraction studies of a new compound: Th13Te24O74

2002 ◽  
Vol 17 (1) ◽  
pp. 32-36 ◽  
Author(s):  
S. N. Tripathi ◽  
S. N. Achary ◽  
P. N. Namboodiri
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns ◽  
Direct Solid ◽  
Measured Density

The compound Th13Te24O74 was prepared by three independent methods, namely, thermal decomposition of ThTe2O6 in oxygen and argon and direct solid-state reaction of ThO2 and TeO2. The X-ray powder diffraction patterns of the three products, by and large, are similar, except for some differences in intensities and extra diffraction lines. The thermal decomposition of ThTe2O6 was carried out in the streams of oxygen and argon by thermogravimetry at a heating rate of 5 K/min in the temperature range of 725–840 °C. The solid-state reaction of ThO2 and TeO2 (13:24) was carried out in a sealed ampoule at 700 °C. The measured density of this compound is 8.23 g/cm3. An orthorhombic lattice with unit cell parameters, a=11.310±0.005 Å, b=14.064±0.006 Å, c=9.056±0.004 Å, and volume of 1440.419±1.088 (Å)3 was determined for this compound.

Kinetic study and modeling of the solid-state reaction Y2BaCuO5 + 3BaCuO2 + 2CuO ⇉ 2YBa2Cu3O6.5−x + xO2

1990 ◽  
Vol 5 (10) ◽  
pp. 2056-2065 ◽  
Author(s):  
Nae-Lih Wu ◽  
Ta-Chin Wei ◽  
Shau-Y Hou ◽  
S-Yen Wong
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Solid State Reaction ◽  
Size Dependence ◽  
Average Particle Size ◽  
Average Particle ◽  
Fractional Conversion ◽  
X Ray ◽  
Unreacted Core ◽  
Kinetics Of

The kinetics of the solid-state reaction Y2BaCuO5 + 3BaCuO2 + 2CuO ⇉ 2YBa2Cu3O6.5−x + xO2 was studied by using x-ray diffractometric and thermogravimetric analyses. Both analyses established that the reaction was well described by the kinetic equation: 1 − 3(1 − F)2/3 + 2(1 − F) = k0 exp(− E/RT)t, where F is the fractional conversion of a calcined powder, E is 520 kcal/molc and, for a rcactant mixture with an average particle size of 3 μm, k0 is 2.03 ⊠ 1092 min−1. An unreacted-core shrinking model was proposed to obtain the particle-size dependence of the reaction, and predicted that the pre-exponential constant k0 changed with reactant particle size by k0 = 2.03 ⊠ 1092(3/d)2 exp(4/d − 4/3), where d is the average reactant particle size in μm.

Kinetics of thermal decomposition of substituted pyridine adducts of N,N'-ethylenebis(salicylideneaminato)cobalt(II) in the solid state

1985 ◽  
Vol 95 (1) ◽  
pp. 227-234 ◽  
Author(s):  
Kikuo Miyokawa ◽  
Masayuki Itoh ◽  
Takummi Etoh ◽  
Setsuko Kinoshita ◽  
Isao Masuda
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Kinetics Of Thermal Decomposition ◽  
Kinetics Of

Darstellung, Kristallstruktur und physikalische Eigenschaften von Oktasilbertrigermanat, Ag8Ge3O10 / Synthesis, Crystal Structure and Physical Properties o f Octasilver Trigermanate, Ag8Ge3O10)

1996 ◽  
Vol 51 (11) ◽  
pp. 1591-1597 ◽  
Author(s):  
Christoph Linke ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
Crystal Structure Analysis ◽  
Temperature Dependent ◽  
X Ray ◽  
Binary Oxides ◽  
Physikalische Eigenschaften

Ag8Ge3O10 was obtained from a mixture of the binary oxides by solid state reaction in the presence of a small amount of water which is acting as an accelerator. Conditions applied were T = 500 °C and p(O2) = 1,2 kbar. According to an X-ray crystal structure analysis the title compound contains four crystallographically independent trigermanate [Ge3O10]8− ions per unit cell (Pc, a = 12.1549(11), b = 10.7375(14), c = 18.5169(20) Å, β = 92.326(10)°, 13448 independent reflections, R1 = 6 ,1 %, wR2 = 13,0%, Z = 8). Thermal decomposition, as recorded by DTA and temperature dependent Guinier photographs, occurs at 520 °C. Ag8Ge3O10 is diamagnetic with a molar susceptibility of -330 ·10−6 cm3 mol−1.

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