scholarly journals Reaction Kinetics and Morphological Study of TiNb2O7 Synthesized by Solid-State Reaction

2017 ◽  
Vol 62 (2) ◽  
pp. 1051-1056
Author(s):  
S.H. Choi ◽  
B. Ali ◽  
K.S. Choi ◽  
S.K. Hyun ◽  
J.J. Sim ◽  
...  
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Reaction Kinetics ◽  
Lithium Ion ◽  
Cost Effective ◽  
Synthesis Temperature ◽  
Reaction Rate Constant ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Quantitative Phase Analysis

AbstractAlthough TiNb2O7is regarded as a material with high application potential in lithium-ion batteries (LIBs) and solid-oxide fuel cells (SOFCs), it has been difficult to find suitable cost-effective conditions for synthesizing it on a commercial scale. In this study, TiNb2O7compounds were synthesized by a solid state synthesis process. For stoichiometrically precise synthesis of the TiNb2O7phase, the starting materials, TiO2and Nb2O5were taken in a 1:1 molar ratio. Activation energy and reaction kinetics of the system were investigated at various synthesis temperatures (800,1000,1200, and 1400°C) and for various holding durations (1,5,10, and 20 h). Furthermore, change in the product morphology and particle size distribution were also evaluated as a function of synthesis temperature and duration. Additionally, quantitative phase analysis was conducted using the Rietveld refinement method. It was found that increases in the synthesis temperature and holding time lead to increase in the mean particle size from 1 to 4.5 μm. The reaction rate constant for the synthesis reaction was also calculated.

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.

Luminescent properties and the morphology of SrMoO4:Eu3+ powders synthesized via combining sol-gel and solid-state route

Open Physics ◽  
2010 ◽  
Vol 8 (5) ◽  
Author(s):  
Qiong Wei ◽  
Donghua Chen
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Ethylenediaminetetraacetic Acid ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Synthesis Temperature ◽  
X Ray Diffraction ◽  
Red Phosphors ◽  
Solid State Route ◽  
Metal Nitrates

AbstractSrMoO4:Eu3+ red phosphors were prepared by combining sol-gel and solid-state route. Citric acid and ethylenediaminetetraacetic acid (EDTA), employed as the chelating agents, were added to the aqueous solutions of metal nitrates. X-ray diffraction (XRD) and photoluminescent spectra techniques (PL) were used to characterize the resultant powders. The results indicated the obtained SrMoO4:Eu3+ phosphors were fine powders with a particle size of 50 nm. The effects of synthesizing conditions were also investigated and optimized, which included the synthesis temperature and the activator concentration on the luminescent intensity. Compared with SrMoO4:Eu3+ phosphors prepared by Solid-state reaction SrMoO4:Eu3+ phosphors prepared by combining sol-gel and solid-state route showed appropriate particle size and a higher emission intensity.

Synthesis of LiFePO4/C Composite Cathode Materials by Solid State Method Using Mixed Iron Sources

2013 ◽  
Vol 734-737 ◽  
pp. 2541-2544
Author(s):  
Wei Wang ◽  
Zheng Zhang ◽  
Dao Wushuang Shi ◽  
Xing Quan Liu
Keyword(s):  
Solid State ◽  
Electrochemical Performance ◽  
Cathode Materials ◽  
Lithium Ion ◽  
Composite Cathode ◽  
Molar Ratio ◽  
Electrochemical Performances ◽  
Solid State Method ◽  
State Reduction ◽  
Solid State Reduction

The olivine LiFePO4/C composite cathode materials for lithium-ion batteries were synthesized by solid state reduction method using mixed iron sources. The effects of different temperatures on the electrochemical performance of as-synthesized cathode materials were investigated and analyzed. The crystal structures and the electrochemical performances were characterized by SEM, galvanostatical charge-discharge testing and AC-impedance, respectively. The results demonstrated that the LiFePO4/C composite cathode material synthesized at 710°C and with 1/2(FeC2O4·2H2O/Fe2O3) molar ratio of mixed iron sources has the better electrochemical performance, it has a discharge capacity of 126.1mAh/g at 0.2C and the capacity is kept at 113.8mAh/g after 20 cycles.

Synthesis and sintering of SiC under high pressure and high temperature

1999 ◽  
Vol 14 (3) ◽  
pp. 906-911 ◽  
Author(s):  
S. K. Bhaumik ◽  
C. Divakar ◽  
S. Usha Devi ◽  
A. K. Singh
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
High Pressure ◽  
Silicon Powder ◽  
Synthesis Temperature ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microscopic Studies ◽  
Simultaneous Synthesis

Starting from elemental powders, simultaneous synthesis and compaction of SiC were conducted at 3 GPa pressure and temperatures in the range 2100–2900 K. The sintered compacts were characterized by x-ray diffraction, microhardness measurements, and microscopic studies. The efficiency of formation of SiC was dependent on the particle size of the silicon powder, crystallinity of the reactant carbon, molar ratio of silicon and carbon, and synthesis temperature and time. Carbon in excess of the stoichiometric amount was required to obtain compacts free from residual silicon. The SiC samples, with a Si: C molar ratio 1: 1.05, prepared at 2100 K for 300 s had a density and hardness of 3.21 g/cm3 (98.8% of theoretical density) and 22 GPa, respectively. The crystal structure of the SiC depended on the synthesis temperature. Pure β–SiC in the temperature range 2100–2500 K, and a mixture of α– and β–SiC above 2500 K were obtained. The β–SiC was highly crystalline and nearly defect-free.

Comparison of Lini0.5Mn1.5O4 and LiMn2O4 for Lithium-Ion Battery

2013 ◽  
Vol 860-863 ◽  
pp. 956-959
Author(s):  
Xing Hua Liang ◽  
Lin Shi ◽  
Yu Si Liu ◽  
Tian Jiao Liu ◽  
Chao Chao Ye ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Electron Microscope ◽  
Solid State ◽  
Scanning Electron Microscope ◽  
Retention Rate ◽  
Lithium Ion ◽  
X Ray ◽  
Charge Discharge ◽  
Scanning Electron

The High Potential Material Lini0.5Mn1.5O4 was Synthesized via Solid-State Reaction.The Surface Morphology and Particle Size of the Sample were Observed by Scanning Electron Microscope(SEM).The Crystal Structure of the Sample was Collected and Analyzed through X-Ray Diffractometry(XRD).The Sample was Charaterized by Charge-Discharge Tests.Results Indicated that the Cycling Retention Rate was about 80%,after being Charge-Diacharged at a Rate of 0.1C in a Voltage of 3.45-4.77V for 10 Times.Compared with Limn2O4,LiNi0.5Mn1.5O4 has good cycle performance.Both of LiNi0.5Mn1.5O4 structure were space group of Fd3m.

scholarly journals Growth of significantly low dimensional zinc orthotitanate (Zn2TiO4) nanoparticles by solid state reaction method

2018 ◽  
Vol 50 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Lizina Khatua ◽  
Rudrashish Panda ◽  
Avanendra Singh ◽  
Arpan Nayak ◽  
Pravakar Satapathy ◽  
...  
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Surface Area ◽  
Solid State Reaction ◽  
Average Particle Size ◽  
Cost Effective ◽  
Solid State Reaction Method ◽  
Average Particle ◽  
Reaction Method ◽  
Low Dimensional

In this work, the ZnO-TiO2 mixed phase nanoparticles were prepared by solid state reaction method by using ZnO and TiO2 powder as precursors. The X-ray diffraction pattern shows a dominant phase of Zinc Orthotitanate (Zn2TiO4). The average particle size (58?18 nm) calculated by the analysing FESEM data closely matches with the particle size calculated by Scherrer?s equation. The calculated average particle size is significantly smaller than the previously published results of nanoparticles, prepared by same method. In the Brunauer-Emmett-Teller (BET) study the specific surface area of the nanoparticles was found as 8.78 m2/g which is similar to the surface area reported in this material prepared by mechanochemical method. The method which we report is simpler and cost effective unlike the previous reported.

Synthesis and characterization of polyaniline nanomaterials with different molar ratio of monomer

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Priyanka S ◽  
Dhachanamoorth N ◽  
Birundha B
Keyword(s):  
Particle Size ◽  
Initial Conditions ◽  
Oxidative Polymerization ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Chemical Oxidative Polymerization ◽  
Good Tool ◽  
Particle Size Analyzer ◽  
Ft Ir

Formation of polymer nanomaterials are achieved by the process of polymerization and there was an availability of different methods such as chemical oxidative polymerization,electro chemical polymerization, In-situ oxidative polymerization and emulsion polymerization etc., Many monomers combine to form polymers under certain conditions by chemical reactions between the monomers. The chemical oxidative polymerization was most commonly used method to synthesize PANI and the synthesis process involved various molar ratio of aniline (0.1M, 0.2M, 0.3M) in which APS was used as an oxidant with dopant of HCl. This study revealed that the properties changed based on their initial conditions. The prepared aromatic polyaniline was characterized by FT-IR, UV-VIS,Particle size analyzer techniques and anti-bacterial activity of the sample was analyzed.FT-IR spectroscopy gives deep view of many  functional groups that were present in a system by measuring vibrational frequencies of chemical bonds involved. UV-VIS was a good tool to identify, characterize and to study the optical properties of nanomaterials.In particle size analyzer, the size of a particle was measured using the instrument laser diffraction particle size analyzer (SALD-2300). The synthesized polyaniline had the tendency to resist the growth of both gram positive and gram negative bacteria. These organic conducting polymers were sometimes called “smart polymers” and have varies application in medical, OLED, solar cell, batteries and sensor etc.,

scholarly journals Effect of Synthesis Temperature on the Crystallization and Growth of In Situ Prepared Nanohydroxyapatite in Chitosan Matrix

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Habiba Elhendawi ◽  
R. M. Felfel ◽  
Bothaina M. Abd El-Hady ◽  
Fikry M. Reicha
Keyword(s):  
Particle Size ◽  
Biomedical Applications ◽  
Particle Growth ◽  
Synthesis Temperature ◽  
Molar Ratio ◽  
Processing Temperature ◽  
Hydroxyapatite Nanoparticles ◽  
Chitosan Matrix ◽  
Coprecipitation Technique

Hydroxyapatite nanoparticles (nHA) have been used in different biomedical applications where certain particle size distribution and morphology are required. Chitosan/hydroxyapatite (CS/HA) nanocomposites were prepared using in situ coprecipitation technique and the effect of the reaction temperature on the crystallization and particle growth of the prepared nanohydroxyapatite particles was investigated. The composites were prepared at different synthesis temperatures (−10, 37, and 60°C). XRD, FTIR, thermal analysis, TEM and SEM techniques were used to characterize the prepared specimens. It was found that the increase in processing temperature had a great affect on particle size and crystal structure of nHA. The low temperature (−10°C) showed inhabitation of the HA growth in c-direction and low crystallinity which was confirmed using XRD and electron diffraction pattern of TEM. Molar ratio of the bone-like apatite layer (Ca/P) for the nanocomposite prepared at 60°C was higher was higher than the composites prepared at lower temperatures (37 and −10°C).

Preparation of Forsterite by Solid State Synthesis Process and its Dielectric Properties

2012 ◽  
Vol 534 ◽  
pp. 110-113 ◽  
Author(s):  
Fei Shi ◽  
Peng Cheng Du ◽  
Jing Xiao Liu ◽  
Ji Wei Wu ◽  
Chun Yuan Luo
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Single Phase ◽  
Raw Materials ◽  
Magnesium Carbonate ◽  
Solid State Synthesis ◽  
Molar Ratio ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
X Ray

Using basic magnesium carbonate (Mg(OH)2•4MgCO3•6H2O) and SiO2 as raw materials, forsterite (Mg2SiO4) was prepared by solid state synthesis process. The optimal process for synthesizing Mg2SiO4 was obtained by adjusting Mg/Si molar ratio and sintering temperature. The crystal phase of the obtained Mg2SiO4 powder was determined by X-ray diffraction (XRD). The results indicate that the single-phase Mg2SiO4 powder can be obtained when the mixtures with Mg/Si molar ratio of 2.05～2.01 were sintered at 1350°C for 3h in the air. The as-prepared Mg2SiO4 ceramic samples which were sintered at 1300～1360°C showed better dielectric properties with εr=7.4 and tanδ =7.5×10-4.

Characterization of Nano-Structured Multiferroic Bismuth Ferrite Produced via Solid State Reaction Route

2013 ◽  
Vol 829 ◽  
pp. 683-687 ◽  
Author(s):  
Ebrahim Mostafavi ◽  
Abolghasem Ataie ◽  
Mostafa Ahmadzadeh
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Calcination Temperature ◽  
Solid State Reaction ◽  
Bismuth Ferrite ◽  
Solid State Reaction Method ◽  
Rietveld Analysis ◽  
Molar Ratio ◽  
Conventional Solid State Reaction ◽  
Mean Particle Size

Multiferroic bismuth ferrite, BiFeO3, was synthesized via conventional solid-state reaction method using Bi2O3, Fe2O3 as starting materials. Effects of Bi2O3/Fe2O3 molar ratio and calcination temperature on the phase composition, morphology and magnetic properties of produced powders were systematically studied using XRD, FESEM/EDS and VSM techniques, respectively. The results revealed that BiFeO3 phase with rhombohedral R3c structure with a mean particle size of 40 nm was formed in the sample processed with a Bi2O3/Fe2O3 molar ratio of 1:1 after calcination at 800 °C. Rietveld analysis which was applied to the x-ray diffraction data via MAUD software indicated high purity of 95%wt for the above sample. Deviation from the stoichiometric molar ratio (Bi2O3/Fe2O3: 0.9, 1.1, 1.2) yielded higher content of the intermediate phases of Bi2Fe4O9 and Bi25FeO40. FESEM studies showed that the mean particle size was increased from 40 to 62 nm by increasing calcination temperature from 800 to 850 °C. VSM results for 1:1 molar ratio samples indicated that increasing the calcination temperature from 800 to 850 °C increased saturation magnetization (Ms) from 0.087 to 0.116 emu/g and also coercive field (Hc) from 60 to 100 Oe.

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