scholarly journals Investigating the Physical Properties of Sintered Alumina in the Presence of MgO Nanopowder

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Mehran Dadkhah ◽  
Abdollah Saboori ◽  
Majid Jafari
Keyword(s):  
Electron Microscope ◽  
Physical Properties ◽  
Grain Boundaries ◽  
Spinel Phase ◽  
Sol Gel ◽  
Inert Atmosphere ◽  
Magnesium Nitrate ◽  
Nitrate Hexahydrate ◽  
Magnesium Nitrate Hexahydrate ◽  
Transmission Electron

Magnesium oxide nanopowder is synthesized using magnesium nitrate hexahydrate and oxalic acid as precursors via the sol-gel method. In order to investigate the effect of magnesia nanopowders on the physical properties of sintered alumina, 0.1, 0.3, and 0.5 wt% of MgO are added to alumina. The prepared specimens were sintered at 1570°C for 4 hours under an inert atmosphere. The morphology and size of nanopowders were characterized by transmission electron microscope (TEM) and scanning electron microscope (SEM). Structural analysis was investigated by means of Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Outcomes show that by increasing the percentage of MgO, spinel phase (MgAl2O4) has been formed in the structure of alumina. During the sintering process, spinel phase diffused through the grain boundaries and pinned the grain boundaries which led to decrease in grain sizes. So, by decreasing the grain size, the physical properties of sintered alumina have improved.

Formation Mechanisms of Sol-Gel Derived Cordierite

2006 ◽  
Vol 45 ◽  
pp. 266-271
Author(s):  
E. Tkalcec ◽  
H. Ivankovic ◽  
J. Macan ◽  
A. Hriberski
Keyword(s):  
Intermediate Phase ◽  
Sol Gel ◽  
Magnesium Nitrate ◽  
Formation Mechanisms ◽  
Sintering Behavior ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Magnesium Nitrate Hexahydrate ◽  
Gel Technique

Gels with cordierite stoichiometry, Mg2Al4Si5O18, were prepared by sol-gel technique using three different starting aluminum sources: nano-sized γ-Al2O3, aluminium nitrate nonahydrate and Al-sec-butoxide, as aluminum sources, using tetraetoxysilane (TEOS) and magnesium nitrate hexahydrate in all three gels as sources for silicon and magnesium. The influence of Al-precursors on formation mechanism and sintering behavior of gels was studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and dilatometry. Gels calcined at 700°C were characterized by different specific surface area, pore sizes and different crystallization sequences. For gel with nano-sized γ-Al2O3 α-cordierite was formed at 1220°C through intermediate MgAl2O4 phase. If aluminum was introduced as Al-sec-butoxide μ-cordierite crystallized in two steps (760 and 1070°C) and the transformation μ-cordierite→α-cordierite occurred at 1250°C. When Al(NO3)3·9H2O was introduced as intermediate phase crystallized MgAl2O4 at ~870°C and μ- cordierite at ~950°C. Both phases reacted with amorphous silica forming α-cordierite at ~1210°C. Compacts prepared from gels with aluminum-nitrates and Al-sec-butoxide, respectively, sintered between 700 and 1000°C, whereas the gel derived from γ-Al2O3 sintered in two steps; between 700- 1000°C and 1010 and 1250°C.

scholarly journals Synthesis of Magnesium Oxide Nanopowder by Thermal Plasma Using Magnesium Nitrate Hexahydrate

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
V. Sirota ◽  
V. Selemenev ◽  
M. Kovaleva ◽  
I. Pavlenko ◽  
K. Mamunin ◽  
...  
Keyword(s):  
Magnesium Oxide ◽  
Thermal Plasma ◽  
Experimental Studies ◽  
Analytical Techniques ◽  
Magnesium Nitrate ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
Magnesium Nitrate Hexahydrate ◽  
Transmission Electron ◽  
Characterization Studies

Magnesium oxide (MgO) nanopowder was synthesized by thermal plasma in a novel thermal DC plasma torch using magnesium nitrate hexahydrate. Magnesium nitrate hexahydrate (Mg(NO3)2·6H2O) was obtained from serpentinite (Mg3Si2O5(OH)4; lizardite) (Halilovskiy array, Orenburg region, Russia). The synthesized samples were characterized by analytical techniques including X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM characterization studies confirmed that MgO nanopowder obtained has periclase structure with high purity, and the particle sizes vary within the range of 100 nm to 150 nm. We believe that the present work will promote further experimental studies on the physical properties and the applications of MgO nanopowders in the fields such as high-densed ceramics, additives in bactericide, and refractory products.

scholarly journals Applications of a simultaneous differential scanning calorimetry–thermomicroscopy system

2021 ◽  
Author(s):  
Gage P. Ashton ◽  
Edward L. Charsley ◽  
Lindsay P. Harding ◽  
Gareth M. B. Parkes
Keyword(s):  
Silver Iodide ◽  
Magnesium Nitrate ◽  
Optical Data ◽  
Nitrate Hexahydrate ◽  
Scanning Calorimetry ◽  
Rubidium Nitrate ◽  
Complex Processes ◽  
Magnesium Nitrate Hexahydrate ◽  
Intensity Measurements ◽  
Reversible Transitions

AbstractA simultaneous DSC–thermomicroscopy system (DSC450 Linkam Scientific) was applied to the study of phase transitions in rubidium nitrate and silver iodide, the oxidation of polyethylene, the thermal degradation of polylactic acid and magnesium nitrate hexahydrate, and the reversible transitions in thermochromic inks. The results demonstrated the benefits of obtaining simultaneous optical data, both images and light intensity measurements, with DSC, particularly in the interpretation of complex processes and the detection of events with small changes in enthalpy.

scholarly journals Effect of Preheating Temperature on Synthesis of Pure BiFeO3 via Sol–Gel Method

Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Pure Bifeo3 ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Preheating Temperature

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.

Hydrothermal Synthesis of MgBO2(OH) Nanomaterials

2011 ◽  
Vol 268-270 ◽  
pp. 195-199
Author(s):  
Guo Sheng Wang ◽  
Kang Jun Wang ◽  
Jia Hou ◽  
Hong Yan Sun ◽  
Ying Ming Wang
Keyword(s):  
Hydrothermal Synthesis ◽  
Crystal Morphology ◽  
Magnesium Nitrate ◽  
Nitrate Hexahydrate ◽  
Temperature Reaction ◽  
Hydrothermal Route ◽  
Magnesium Borate ◽  
Reaction Condition ◽  
Magnesium Nitrate Hexahydrate ◽  
Composition Structure

Magnesium borate hydroxide (MgBO2(OH) ) were synthesized using magnesium nitrate hexahydrate(MgNO3.6H2O) and borax decahydrate(Na2B4O7.10H2O) by hydrothermal route. Effect of reaction temperature , reaction time and water's volume on the composition , structure , and crystal morphology of the products were investigated, and the products were characterized by XRD and SEM. The results indicated that all of the products were szaibelyite with the reaction condition investigated, and crystal morphology could be tailored via varying the reaction condition.

Densities of nitrate hydrates used as phase change materials

2017 ◽  
Vol 10 (2) ◽  
pp. 79-83
Author(s):  
Vladimír Danielik ◽  
Dominika Szendreiová
Keyword(s):  
Phase Change Materials ◽  
Liquid Mixtures ◽  
Liquid System ◽  
Zinc Nitrate ◽  
Magnesium Nitrate ◽  
Zinc Nitrate Hexahydrate ◽  
Nitrate Hexahydrate ◽  
Temperature Dependency ◽  
Magnesium Nitrate Hexahydrate ◽  
Different Temperatures

AbstractTemperature dependency of densities of the liquid system magnesium nitrate hexahydrate - zinc nitrate hexahydrate was measured. Densities of liquid mixtures were experimentally measured at different temperatures by a method using submersible corpuscle. Based on the obtained data, temperature dependence on the density was obtained. A model describing the density in the whole concentration range very well was created.

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