Influence of Synthesis Temperature on the ZnNb2O6 Powders Prepared via Co-Precipitation Method

2014 ◽  
Vol 1033-1034 ◽  
pp. 1044-1047
Author(s):  
Yong Du ◽  
Jin Liang Huang ◽  
Yong Jun Gu
Keyword(s):  
Particle Size ◽  
Phase Composition ◽  
Chemical Composition ◽  
High Purity ◽  
Raw Materials ◽  
Particle Morphology ◽  
Synthesis Temperature ◽  
Coprecipitation Method ◽  
Precipitation Method ◽  
Co Precipitation

ZnNb2O6powder was successfully synthesized via coprecipitation method with Nb2O5、Zn(NO3)2·6H2O as raw materials and ammonia as precipitant agent. This precursor on heating at750°C, produced ZN powders. Phase composition, morphology and chemical composition were studied via a combination of XRD, TEM and EDS technique. The effects of synthesis temperature on phase composition and particle morphology were investigated in this paper. The results showed that with the increase of the synthesis temperature, the particle size decreases. We could get the ZnNb2O6powder with high purity, fine crystalline when the synthesis temperature is at 50°C.

Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

2018 ◽  
Vol 281 ◽  
pp. 40-45
Author(s):  
Jie Guang Song ◽  
Lin Chen ◽  
Cai Liang Pang ◽  
Jia Zhang ◽  
Xian Zhong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Hydrothermal Reaction ◽  
Synthesis Method ◽  
Particle Morphology ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Powder Materials ◽  
Co Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

Preparation and Evaluation of BaxSr(x-1)CoyFe(y-1)O3−δ Nanomaterial for SOFC Cathode by Oxalate Co-Precipitation (x=0.2, y=0.8)

2011 ◽  
Vol 52-54 ◽  
pp. 1177-1181 ◽  
Author(s):  
Mojgan Ahmadrezaei ◽  
Andanastuti Muchtar ◽  
Norhamidi Muhamad ◽  
Chou Yong Tan
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
High Purity ◽  
Fine Particle ◽  
Ammonium Oxalate ◽  
Perovskite Oxide ◽  
Precipitation Method ◽  
High Homogeneity ◽  
Fine Particle Size ◽  
Co Precipitation

A recently reported promising new perovskite oxide cathode material, Ba0.2Sr0.8Co0.8Fe0.2O3−δ, (BSCF) (with x = 0.2 and y = 0.8) of high purity for intermediate-temperature solid oxide fuel cells (IT-SOFCs) was synthesised in the current work by using the co-precipitation method. The result indicated a precursor with a well-defined composition of fine particle size, high homogeneity, and high reactivity. After calcining has been developed at 900°C, the individual oxides from ammonium oxalate were alloyed into nanostructured perovskite (with x = 0.2 and y = 0.8) Ba0.2Sr0.8Co0.8Fe0.2O3 of high purity. The thermal properties, phase constituents, surface area and microstructure of the samples were characterised by TGA, XRD, BET, SEM and EDX techniques respectively. The results show that the BSCF powders have cubic perovskite-type structure with fine particle size, high surface area and high homogeneity. The current method employed is found to be very reliable for the synthesis of BSCF.

scholarly journals Impact of Iron on the Fe–Co–Ni Ternary Nanocomposites Structural and Magnetic Features Obtained via Chemical Precipitation Followed by Reduction Process for Various Magnetically Coupled Devices Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 341
Author(s):  
Tien Hiep Nguyen ◽  
Gopalu Karunakaran ◽  
Yu.V. Konyukhov ◽  
Nguyen Van Minh ◽  
D.Yu. Karpenkov ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Reduction Process ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Magnetic Characteristics ◽  
Reduction Temperature ◽  
Fe Content ◽  
Magnetic Features ◽  
Co Precipitation

This paper presents the synthesis of Fe–Co–Ni nanocomposites by chemical precipitation, followed by a reduction process. It was found that the influence of the chemical composition and reduction temperature greatly alters the phase formation, its structures, particle size distribution, and magnetic properties of Fe–Co–Ni nanocomposites. The initial hydroxides of Fe–Co–Ni combinations were prepared by the co-precipitation method from nitrate precursors and precipitated using alkali. The reduction process was carried out by hydrogen in the temperature range of 300–500 °C under isothermal conditions. The nanocomposites had metallic and intermetallic phases with different lattice parameter values due to the increase in Fe content. In this paper, we showed that the values of the magnetic parameters of nanocomposites can be controlled in the ranges of MS = 7.6–192.5 Am2/kg, Mr = 0.4–39.7 Am2/kg, Mr/Ms = 0.02–0.32, and HcM = 4.72–60.68 kA/m by regulating the composition and reduction temperature of the Fe–Co–Ni composites. Due to the reduction process, drastic variations in the magnetic features result from the intermetallic and metallic face formation. The variation in magnetic characteristics is guided by the reduction degree, particle size growth, and crystallinity enhancement. Moreover, the reduction of the surface spins fraction of the nanocomposites under their growth induced an increase in the saturation magnetization. This is the first report where the influence of Fe content on the Fe–Co–Ni ternary system phase content and magnetic properties was evaluated. The Fe–Co–Ni ternary nanocomposites obtained by co-precipitation, followed by the hydrogen reduction led to the formation of better magnetic materials for various magnetically coupled device applications.

Aluminate Green Phosphor with Small Particle Size Used for PDP via Co-Precipitation Method

2011 ◽  
Vol 295-297 ◽  
pp. 890-895
Author(s):  
Yan Dong ◽  
Yang Zhou ◽  
Xue Lin Han ◽  
Wei Jie Gu
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Small Particle ◽  
High Efficiency ◽  
Particle Growth ◽  
Solid State Reaction Method ◽  
Precipitation Method ◽  
Small Particle Size ◽  
Green Phosphor ◽  
Co Precipitation

Mg doped BaAl12O19:Mn2+ phosphor is one of the most efficient green phosphors for PDP. It is difficult to prepare the phosphor both have small particle size (< 3μm) and high luminescence. In the present work, a BaAl12O19:Mn2+ phosphor with small particle size was synthesized by the chemical co-precipitation method. Phase transformation and particle growth process during calcining process were investigated. The nucleation process was also discussed. The results show that, the phase transformation is complicated, the transition phases include BaCO3, γ-Al2O3, BaF2, BaAl2O4 and two phases contain Mn; The BaAl12O19 phase is formed from the reaction between BaAl2O4 phase and γ-Al2O3 phase, no a-Al2O3 phase appears during the entire process; The formation temperature of pure BaAl12O19 phase is 1200°C, which is lower than that in the high-temperature solid state reaction method. High efficiency BaAl12O19:Mn2+ phosphor with small particle size (< 2μm) and hexagonal flaky shape can be prepared by this method.

Preparation and Electrochemical Performance of Mn3O4/GR Composites Electrode Material in Supercapacitors

2019 ◽  
Vol 807 ◽  
pp. 50-56
Author(s):  
Yun Long Zhou ◽  
Zhi Biao Hu ◽  
Li Mei Wu ◽  
Jiao Hao Wu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Manganese Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
A Current ◽  
Discharge Test

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

ChemInform Abstract: Preparation of BaMgAl10O17:Eu2+ Phosphor with Small Particle Size by Co-Precipitation Method.

ChemInform ◽  
2011 ◽  
Vol 42 (13) ◽  
pp. no-no
Author(s):  
Yan Dong ◽  
Zhisen Wu ◽  
Xuelin Han ◽  
Rong Chen ◽  
Weijie Gu
Keyword(s):  
Particle Size ◽  
Small Particle ◽  
Precipitation Method ◽  
Small Particle Size ◽  
Co Precipitation

The Influence of Calcination Temperature on Quantitative Phase of Hematite from Iron Stone Tanah Laut

2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Co Precipitation

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.

Morphology-Controlled CaCO3 Nanostructures by Modified Co-Precipitation in Pulsed Mode

2015 ◽  
Vol 752-753 ◽  
pp. 148-153
Author(s):  
M.M. Nassar ◽  
Taha Ebrahiem Farrag ◽  
M.S. Mahmoud ◽  
Sayed Abdelmonem
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Rotation Speed ◽  
Average Particle Size ◽  
Calcium Nitrate ◽  
Precipitation Method ◽  
Average Particle ◽  
X Ray ◽  
Co Precipitation ◽  
Pulsed Mixing

Calcium carbonate nanoparticles and nanorods were synthesized by precipitation from saturated sodium carbonate and calcium nitrate aqueous solutions through co precipitation method. A new rout of synthesis was done by both using pulsed mixing method and controlling the addition of calcium nitrate. The effect of the agitation speed, and the temperature on particle size and morphology were investigated. Particles were characterized using X-ray Microanalysis, X-ray analysis (XRD) and scanning electron microscopy (SEM). The results indicated that increasing the mixer rotation speed from 3425 to 15900 (rpm) decreases the average particle size to 64±7 nm. A rapid nucleation then aggregation induced by excessive shear force phenomena could explain this observation. Moreover, by increasing the reaction temperature, the products were converted from nanoparticle to nanorods. The maximum attainable aspect ratio was 6.23 at temperature of 75°C and rotation speed of 3425. Generally, temperature raise promoted a significant homoepitaxial growth in one direction toward the formation of calcite nanorods. Overall, this study can open new avenues to control the morphology of the calcium carbonate nanostructures.

Study on the Characterization of Zinc Ferrite High-Temperature Coal Gas Desulfurization Agent

2010 ◽  
Vol 129-131 ◽  
pp. 1233-1237
Author(s):  
Hong Yan Xu ◽  
Mei Sheng Liang ◽  
Chun Hu Li
Keyword(s):  
Zinc Ferrite ◽  
Raw Materials ◽  
Particle Diameter ◽  
Textural Properties ◽  
Zinc Nitrate ◽  
Gas Absorption ◽  
Precipitation Method ◽  
Ferric Nitrate ◽  
The One ◽  
Co Precipitation

Using ferric nitrate, zinc nitrate, ammonia liquor and binder as main raw materials, five kinds of zinc ferrite sorbents were prepared by the co-precipitation method. The effects of the different binders on the structure and texture of zinc ferrite sorbents were investigated. The morphology, composite structure, pore properties, and mechanical strength were studied by using modern several physicochemical techniques such as powder X-ray diffraction (XRD), scanning electronic microscopy (SEM), strength tester and gas absorption meter. It is showed that spinel structure ZnFe2O4 is not affected by different binders，and its particle diameter is in micron leve1. The spinel structures are present in the sorbents that have been calcined at 750 0C.. The sorbent employed kaolinite as binder is the best one of the five types of sorbents for desulfurization, while the one employed diatomite is the worst.Different binders modify the textural properties, modifying consequently the sorbent reactivity. Furthermore, the reactivity and sulfur capacity of sorbents are increasing with an increase in the pore volume.

Synthesis of pigments in Fe2O3-Al2O3-CoO by co-precipitation method

2017 ◽  
Vol 46 (5) ◽  
pp. 356-361 ◽  
Author(s):  
Liliya Frolova ◽  
Alexander Pivovarov ◽  
Tatyana Butyrina
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Treatment Temperature ◽  
Precipitation Method ◽  
Colour Properties ◽  
X Ray Diffraction ◽  
Content Type ◽  
Composition Property ◽  
Yellow Pigments ◽  
Co Precipitation

Purpose The purpose of this work is to study the patterns of pigment colour formation and to develop metal compositions for obtaining spinels using the precipitation and heat treatment methods. Design/methodology/approach Precursor materials were prepared using co-precipitation method. Phase composition of pigments were determined by X-ray diffraction. Colour of pigments was determined spectrophotometry. Modelling of colour formation was performed using simplex method. Planning in the future to carry out full synthesis of pigments of blue, red and yellow colours. Findings The paper deals with the results of theoretical and experimental research on the synthesis pigments of blue, red and yellow colours based on Fe-Co-Al-O spinel. The influence of the chromophore cation content and the heat treatment temperature on optical and colour characteristics of pigments were studied. Originality/value The resulting composition-property diagrams make it possible to evaluate the effect of chromophore cations and heat treatment on the colour formation for Fe2O3-Al2O3-CoO system. Crystal-phase composition of the pigments is installed and its relationship with the optical colour characteristics. That makes it possible carry out targeted synthesis of pigments blue, red and yellow colours in further. The phase composition of pigments and its relationship with optical and colour properties has been established thus enabling the directed synthesis of blue, red and yellow pigments.

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