Strontium and calcium zirconyl citrates as precursors for the low-temperature synthesis of SrZrO3 and CaZrO3 fine powders

1997 ◽  
Vol 12 (10) ◽  
pp. 2665-2672 ◽  
Author(s):  
M. Rajendran ◽  
M. Subba Rao
Keyword(s):  
Thermal Decomposition ◽  
Molecular Precursors ◽  
Fine Powders ◽  
Sequence Of Events ◽  
Physico Chemical ◽  
Multistep Process ◽  
Precursor Decomposition ◽  
Decomposition Behavior ◽  
Citrate Precursors ◽  
Microscopic Techniques

Synthesis and the thermal decomposition behavior of new molecular precursors, strontium, and calcium zirconyl citrates are presented. The pathway to the metazirconate formation has been found to proceed through a multistep process. The precursors yield SrZrO3 and CaZrO3 fine powders at temperatures as low as 650 °C. Physico-chemical, spectroscopic, thermoanalytical, and microscopic techniques have enabled the identification of the sequence of events leading to the perovskite formation and proposition of a thermolysis scheme. Retention of the molecular level mixing of the metal ions during the course of the precursor decomposition is supported by these techniques. Prior to the formation of MZrO3 (M = Sr and Ca) an ionic oxycarbonate, M2Zr2O5CO3 (M = Sr and Ca), intermediate is produced by the thermal decomposition of the citrate precursors.

Influence of thermal decomposition behavior of titanium precursors on (Ba,Sr)TiO3 thin films

2001 ◽  
Vol 11 (PR3) ◽  
pp. Pr3-675-Pr3-682 ◽  
Author(s):  
Y. S. Min ◽  
Y. J. Cho ◽  
D. Kim ◽  
J. H. Lee ◽  
B. M. Kim ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Decomposition ◽  
Thermal Decomposition Behavior ◽  
Decomposition Behavior

scholarly journals Preparation of Few-Layered WS2 and Its Thermal Catalysis for Dihydroxylammonium-5,5′-Bistetrazole-1,1′-Diolate

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Yiping Shang ◽  
Wu Yang ◽  
Yabei Xu ◽  
Siru Pan ◽  
Huayu Wang ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Analysis Data ◽  
Decomposition Temperature ◽  
Thermal Excitation ◽  
Layered Semiconductor ◽  
Initial Decomposition Temperature ◽  
Thermal Decomposition Behavior ◽  
Decomposition Behavior ◽  
Catalytic Effects

In this study, few-layered tungsten disulfide (WS2) was prepared using a liquid phase exfoliation (LPE) method, and its thermal catalytic effects on an important kind of energetic salts, dihydroxylammonium-5,5′-bistetrazole-1,1′-diolate (TKX-50), were investigated. Few-layered WS2 nanosheets were obtained successfully from LPE process. And the effects of the catalytic activity of the bulk and few-layered WS2 on the thermal decomposition behavior of TKX-50 were studied by using synchronous thermal analysis (STA). Moreover, the thermal analysis data was analyzed furtherly by using the thermokinetic software AKTS. The results showed the WS2 materials had an intrinsic thermal catalysis performance for TKX-50 thermal decomposition. With the few-layered WS2 added, the initial decomposition temperature and activation energy (Ea) of TKX-50 had been decreased more efficiently. A possible thermal catalysis decomposition mechanism was proposed based on WS2. Two dimensional-layered semiconductor WS2 materials under thermal excitation can promote the primary decomposition of TKX-50 by enhancing the H-transfer progress.

Preparation of YBa2Cu3O7−x precursors from a fused eutectic of sodium and potassium hydroxides

1989 ◽  
Vol 4 (6) ◽  
pp. 1307-1311 ◽  
Author(s):  
Nicholas Coppa ◽  
Daniel H. Nichols ◽  
John W. Schwegler ◽  
J. E. Crow ◽  
G. H. Myer ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Potassium Hydroxide ◽  
Product Formation ◽  
Mechanical Grinding ◽  
Reaction Conditions ◽  
Fine Powders ◽  
Yttrium Barium ◽  
Sodium And Potassium

A method for preparing YBa2Cu3O7−x from the simultaneous thermal decomposition of the nitrates of yttrium, barium, and copper in an anhydrous fused eutectic of sodium and potassium hydroxide is described. This method eliminates the need for any mechanical grinding or the introduction of carbon containing anions. Products formed are fine powders (∼1 μm) having mole ratios 1.00Y:2.00Ba:3.06Cu.X-ray diffraction analyses reveal that the initial products are Y(OH)3, BaO2, and CuO, which when air calcinated/oxygen annealed at 900–950 °C form the superconducting YBa2Cu3O7−x A mechanism is postulated for product formation as a function of reaction conditions.

scholarly journals Thermal degradation behaviour of some polydithiooxamide metal complexes

2006 ◽  
Vol 31 (1) ◽  
pp. 45-52 ◽  
Author(s):  
H. Al-Maydama ◽  
A. El-Shekeil ◽  
M. A. Khalid ◽  
A. Al-Karbouly
Keyword(s):  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Integral Method ◽  
Valence Shell ◽  
Degradation Behaviour ◽  
Thermal Stabilities ◽  
Electron Pairs ◽  
Thermal Decomposition Behavior ◽  
The Difference ◽  
Decomposition Behavior

The thermal decomposition behavior of the Fe(II), Co(II), Ni(II) and Zn(II) complexes of polydithiooxamide has been investigated by thermogravimetric analysis (TGA) at a heating rate of 20°C min-1 under nitrogen. The Coats-Redfern integral method is used to evaluate the kinetic parameters for the successive steps in the decomposition sequence observed in the TGA curves. The processes of thermal decomposition taking place in the four complexes are studied comparatively as the TGA curves indicate the difference in the thermal decomposition behavior of these complexes. The thermal stabilities of these complexes are discussed in terms of repulsion among electron pairs in the valence shell of the central ion and electronegativity effects.

scholarly journals A Novel Recycling Technology of Bamboo Using NaOH

2018 ◽  
Vol 2 (5) ◽  
pp. 7-12
Author(s):  
Keyword(s):  
Thermal Decomposition ◽  
Optimum Condition ◽  
Inert Atmosphere ◽  
Bamboo Forest ◽  
Alkali Fusion ◽  
Combustible Gas ◽  
Thermal Decomposition Behavior ◽  
Recycling Technology ◽  
Decomposition Behavior ◽  
Alkali Hydroxide

The bamboo industry in Japan is declined, and disordered bamboo forests are increasing. Although maintenance of bamboo forest is needed, a large amount of bamboo wastes after logging is generated and left untreated. Therefore, new utilization of bamboo wastes after logging are desired. In this research, we aimed to develop a new recycling technology for bamboo using alkali hydroxide. By pyrolyzing bamboo using hydroxide under an inert atmosphere, thermal decomposition of organic contents and alkali fusion of silica component inside the bamboo were carried out simultaneously to recover combustible gas, charcoal and silica component. The thermal decomposition behavior of bamboo, the properties of the obtained charcoal and extraction of silica in the presence of alkali hydroxide were investigated, and the optimum condition of bamboo recycling treatment was examined. As a result, it was found that when 1 g of bamboo was pyrolyzed at higher than 500 °C with 3 g NaOH ,the almost silica was extracted, a large amount of gas generated, and a carbonized material with specific surface area of about more than 1100 m2 /g was obtained.

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