Synthesis of nano-crystalline (Ni/NiO)–YSZ by microwave-assisted combustion synthesis method: The influence of pH of precursor solution

The microwave assisted combustion synthesis (MACS) as a new, quick and low cost synthesis method was used for preparation of niobium pentoxide (Nb2O5) powders. The present paper investigated the effect of reactant concentrations (ammonium niobium oxalate, urea and ammonium nitrate) on the characteristics of Nb2O5 nanoparticles. Three samples were synthesized with stoichiometric ratio between the fuel and oxidant (C1), excess of oxidant (C2) and excess of fuel (C3). In all samples, Nb2O5 crystalline nanoparticles with irregular morphology were detected. The synthesis of nanoparticles with smaller diameter in the C2 and C3 samples was confirmed by greater values of band gap energy measured through UV-Visible diffuse reflectance spectroscopy (indicating quantum confinement) and by the Rietveld refinement of X-ray diffraction patterns. The results showed that the amounts of oxidant and fuel can change synthesis temperature, influencing the final characteristics of the particles, such as size and existent phases. In these cases the excess of oxidant and fuel in the C2 and C3 samples, respectively, decreases the average synthesis temperature and decelerates the particle growth and the formation of the monoclinic phase.

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Synthesis of nano-crystalline TaC−TaB[sub 2] by microwave-assisted combustion synthesis

10.1063/1.4849226 ◽

2013 ◽

Author(s):

Behzad Aminikia

Keyword(s):

Combustion Synthesis ◽

Microwave Assisted ◽

Nano Crystalline

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Microwave-Assisted Combustion Synthesis of Nanocrystalline ZnO Powders Using Zinc Nitrate and Various Amount of Organic Fuels as Reactants: Influence of Reactant Parameters - A Status Review

Nano Hybrids ◽

10.4028/www.scientific.net/nh.6.75 ◽

2014 ◽

Vol 6 ◽

pp. 75-110

Author(s):

L.C. Nehru ◽

C. Sanjeeviraja

Keyword(s):

Combustion Synthesis ◽

Flame Temperature ◽

Synthesis Method ◽

Zinc Nitrate ◽

Adiabatic Flame Temperature ◽

Molar Ratios ◽

Microwave Assisted ◽

Organic Fuels ◽

Zno Powders ◽

Xrd Techniques

Nanocrystalline ZnO powders have been synthesized by a novel and simple microwave-assisted combustion synthesis method using urea, glycine, carbohydrazine and citric acid as fuels and zinc nitrate as oxidant. The starting materials were directly mixed and a slurry precursor with high homogeneity was formed due to the hygroscopicity of the reactants. The precursor could be ignited at room temperature, resulting in dry, loose and voluminous ZnO powders. An interpretation based on an adiabatic flame temperature, amount of gases produced during reaction for various fuel-to-oxidizer molar ratios (ψ), has been proposed for the nature of combustion and its correlation with the characteristics of as-synthesized product. The variation of adiabatic flame temperature (Tad) with the ψ value was calculated theoretically according to the thermodynamic concept. The reaction process of the precursor was investigated by XRD techniques.

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Redox Effects in Self-Sustainiing Combustion Synthesis of Oxide Ceramic Powders

MRS Proceedings ◽

10.1557/proc-249-159 ◽

1991 ◽

Vol 249 ◽

Cited By ~ 18

Author(s):

L.A. Chick ◽

G.D. Maupin ◽

G.L. Graff ◽

L.R. Pederson ◽

D.E. Mccready ◽

...

Keyword(s):

Combustion Synthesis ◽

Synthesis Method ◽

Precursor Solution ◽

The Self ◽

Oxide Ceramic ◽

Ceramic Powders ◽

Oxide Product ◽

Oxide Powders ◽

Glycine Nitrate Process

ABSTRACTThe glycine/nitrate process (GNP) is a combustion synthesis method that is particularly useful for synthesizing ultra-fine, multi-component oxide powders. During the self-sustaining combustion, the precursor solution is rapidly converted into an oxide product with glycine serving as the fuel and nitrates providing the oxidant. This paper examines the effects of altering the fuel/oxidant ratio on the characteristics of the product. Examples discussed include La(Sr)CrO3 and La(Sr)FeO3 perovskites and NiO.

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Preparation of Mo (Si, Al) 2 by Microwave Assisted Combustion Synthesis

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.103.509 ◽

2011 ◽

Vol 103 ◽

pp. 509-512 ◽

Cited By ~ 2

Author(s):

Si Wen Tang ◽

Jian Hui Yan ◽

Cheng Zhang Peng

Keyword(s):

Phase Composition ◽

Combustion Synthesis ◽

Phase Structure ◽

Heating Temperature ◽

Synthesis Method ◽

Sem Analysis ◽

Microwave Energy ◽

Microwave Assisted Synthesis ◽

Microwave Assisted ◽

Al Substitution

Al substituted MoSi2composites were prepared by using microwave assisted synthesis method, which is a self-propagation synthesis ignited by microwave energy. The composition and microstructure of as combusted powder had been detected by XRD and SEM analysis. Result shows that the pre-heating temperature and phase composition of microwave assisted combustion synthesis is largely influenced by the content of aluminum. The phase structure of Mo(Si, Al)2alter from a mixture of MoSi2and Mo5Si3to nearly pure Mo (Si, Al)2with the increasing of Al substitution. The main mechanism is dissolution separation..

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