Synthesis of YAG Powders by Co-Precipitation Method

2014 ◽  
Vol 602-603 ◽  
pp. 110-113 ◽  
Author(s):  
Yan Juan Li ◽  
Ying Chun Zhang ◽  
Jia Xun Leng
Keyword(s):  
Crystal Structure ◽  
Metal Ion ◽  
Yttrium Aluminum Garnet ◽  
Raw Materials ◽  
Nitrate Solution ◽  
Particle Size Analysis ◽  
Precipitation Method ◽  
Size Analysis ◽  
Yttrium Nitrate ◽  
Co Precipitation

In this paper, yttrium aluminum garnet (YAG) powders were synthesized by the normal-strike co-precipitation method (adding precipitant solution to the metal nitrate solution). Aluminum nitrate (Al (NO3)39H2O) and yttrium nitrate (Y(NO3)36H2O) were used as raw materials and ammonium hydrogen carbonate (AHC) was used as the precipitant. The precursor was calcined at the temperature of 900-1200 °C for 2 hours. The crystal structure and microstructure of YAG powders were investigated and analyzed by XRD, FESEM, TG-DTA and laser particle size analysis. The results show that the concentration of metal ion and AHC have a significant effect on crystal structure of YAG powders, and pure YAG powders were obtained at 1000 °C when the concentration of Al3+was 0.1 mol/L and the concentration of AHC was 1 mol/L. The average primary crystallites particle sizes were ranged from 50 nm to100 nm in diameter. nanosize YAG powders with excellent properties and good dispersity can be produced at the temperature of 1100 °C.

scholarly journals Synthesis and Characterization of Photoluminescent PVA/ZnS: Mn2+ Nanocomposites

2013 ◽  
Vol 12 (1) ◽  
pp. 31-37
Author(s):  
Priya L
Keyword(s):  
Aqueous Media ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Precipitation Method ◽  
Size Analysis ◽  
Average Particle ◽  
Energy Gaps ◽  
Bulk Absorption ◽  
Co Precipitation

A ZnS nanoparticle doped with Mn2+ is synthesized in aqueous media and PVA using chemical co-precipitation method. This colloid was analyzed using uv-vis spectrophotometry. It is observed that the absorption peak blue shifts as compared to the bulk absorption of ZnS suggesting the nanoparticle formation. The energy gaps of these nanoparticles were calculated from the uv-vis spectra. The average particle size analysis is carried out using XRD. Photoluminescence of PVA/ ZnS:Mn2+ is studied. It is observed that the composite sample exhibits an orange emission peak as is reported for pure ZnS: Mn2+.

Ultra-Small Superparamagnetic Iron Oxide Nanoparticles as MRI Contrast Enhancing Agents

2008 ◽  
Vol 47-50 ◽  
pp. 1076-1079
Author(s):  
M.A. Do ◽  
H.J. Lee ◽  
J.H. Yeum ◽  
Y.M. Chang ◽  
H.D. Ghim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Superparamagnetic Iron Oxide ◽  
Particle Size Analysis ◽  
Superparamagnetic Iron Oxide Nanoparticles ◽  
Precipitation Method ◽  
Size Analysis ◽  
Oxide Nanoparticles ◽  
Co Precipitation

Ultrasmall superparamagnetic iron oxide nanoparticles (USPION) as magnetic resonance imaging were synthesized through a sonochemical co-precipitation method with poly (ethyleneimine) (PEI). The size of the USPION was controlled by poly (ethyleneimine) (PEI) contents, ultrasonic exposure time, and Na4OH concentration. The characteristics of PEI-USPION were studied by X-ray diffractometry, magnetic property measurement system, scanning electron microscopy, transmission electron microscopy, and particle size analysis. The PEI-USPION had an average size of 5~10nm with a narrow size distribution, a perfect magnetite crystal structure, and high saturation magnetization.

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

scholarly journals Pre-treatment of desalination feed seawater by Jordanian Tripoli, Pozzolana, and Feldspar: Batch experiments

2011 ◽  
Vol 17 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Aiman Al-Rawajfeh ◽  
Khaldoon Al-Whoosh ◽  
Dwairi Al ◽  
Ahmad Al-Maaberah ◽  
Amer Tarawneh
Keyword(s):  
Layered Double Hydroxide ◽  
Metal Ion ◽  
Raw Materials ◽  
Batch Experiments ◽  
Initial Concentration ◽  
Considerable Potential ◽  
Ion Concentrations ◽  
Pre Treatment ◽  
Co Precipitation ◽  
Double Hydroxide

In this research, composites of layered double hydroxide (LDH) with three Jordanian natural raw materials; Tripoli (T), Pozzolana (P) and Feldspar (F) were prepared by co-precipitation and have been used for feed seawater pre-treatment. The data reveals that percent adsorption decreased with increase in initial concentration, but the actual amount of adsorbed ions per unit mass of LDH/T-P-F increased with increase in metal ion concentrations. The values of ?Go were negative and within 21 to 26 KJ/mol, while the values of ?Ho and ?So were positive and within the range of 0.1 to 25 KJ/mol. The values of ?H?, ?S?, and ?G? indicate the favorability of physisorption and show that the LDH/T-P-F composites have a considerable potential as adsorbents for the removal of ions from seawater.

Preparation of Amorphous Nanosilica from Philippine Waste Rice Hull via Acid Precipitation Method

2016 ◽  
Vol 864 ◽  
pp. 112-116
Author(s):  
Rinlee Butch M. Cervera ◽  
Emie A. Salamangkit-Mirasol
Keyword(s):  
Electron Microscopy ◽  
Low Cost ◽  
Agricultural Waste ◽  
Acid Precipitation ◽  
Particle Size Analysis ◽  
Precipitation Method ◽  
Rice Hull ◽  
Size Analysis ◽  
Rice Hull Ash ◽  
Transmission Electron

Rice hull or rice husk (RH) is an agricultural waste obtained from milling rice grains. Since RH has no commercial value and is difficult to use in agriculture, its volume is often reduced through open field burning which is an environmental hazard. In this study, amorphous nanosilica from Philippine waste RH was prepared via acid precipitation method. The synthesized samples were fully characterized for its microstructural properties. X-ray diffraction pattern reveals that the structure of the prepared sample is amorphous in nature while Fourier transform infrared spectrum showed the different vibration bands of the synthesized sample. Scanning electron microscopy (SEM) and particle size analysis (PSA) confirmed the presence of agglomerated silica particles. On the other hand, transmission electron microscopy (TEM) revealed an amorphous sample with grain sizes of about 5 to 20 nanometer range and has about 95 % purity according to EDS analyses. The elemental mapping also suggests that leaching of rice hull ash effectively removed the metallic impurity such as potassium element in the material. Hence, amorphous nanosilica was successfully prepared via a low-cost acid precipitation method from Philippine waste rice hull.

scholarly journals Synthesis and characterization of N, O-donor Schiff base capped ZnS NPs as a sensor for fluorescence selective detection of Fe 3+, Cr 2+ and Cd 2+ ions

2018 ◽  
Vol 4 (4) ◽  
pp. 151-162
Author(s):  
Dasari Ayodhya ◽  
Guttena Veerabhadram
Keyword(s):  
Schiff Base ◽  
Quantum Confinement ◽  
Metal Ion ◽  
Quantum Confinement Effect ◽  
Precipitation Method ◽  
Donor Ligand ◽  
Zinc Sulfide Nanoparticles ◽  
Co Precipitation ◽  
Selective Sensor

We report the simple synthesis of zinc sulfide nanoparticles (ZnSNPs) by a co-precipitation method using Schiff base, (2-[(4-methoxy-phenylimino)-methyl]-4-nitro phenol) as a capping agent. Here, Schiff base is also used as N, O-donor ligand to control the morphology of NPs and fluorescence interactions. The formation of ZnSNPs and their optical, structural, thermal properties and morphologies were studied by means of UV–vis DRS, fluorescence, FTIR, XRD, SEM, TEM, zeta potential and TGA. The optical properties and quantum confinement effect of the products were confirmed by means of spectroscopic measurements. XRD and TEM image shows that the synthesized ZnSNPs have cubic structures with a diameter of about less than 10 nm. The prepared ZnSNPs exhibited as a selective probe detection of Fe3+, Cr2+ and Cd2+ ions by fluorometrically and the emission band which disappears in the presence of increasing concentrations of Fe3+, Cr2+ and Cd2+ ions. Based on the fluorescence quenching of the NPs in the presence of metal ion of interest, the feasibility of their determinations was examined according to the Stern-Volmer equation. Our work suggested that Schiff base capped ZnSNPs could be a potential selective sensor in the detection of heavy metal ions.

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.

Crystal structure and magnetic properties of Gd–Cu substituted M-type Sr-hexaferrites synthesized by the co-precipitation method

2019 ◽  
Vol 546 (1) ◽  
pp. 48-56
Author(s):  
Ze Wu ◽  
Yang Song ◽  
Ruonan Zhang ◽  
Lianwei Shan ◽  
Limin Dong ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Precipitation Method ◽  
Co Precipitation

Analysis of the Incorporation of Scheelite Residue in Kaolinitic Clay of Boa Saúde-RN

2012 ◽  
Vol 727-728 ◽  
pp. 844-849 ◽  
Author(s):  
Tércio G. Machado ◽  
Uilame Umbelino Gomes ◽  
Flanelson M. Monteiro ◽  
Samara M. Valcacer ◽  
Gilson G. da Silva
Keyword(s):  
Raw Materials ◽  
Particle Size Analysis ◽  
Northeastern Brazil ◽  
Size Analysis ◽  
Bending Tests ◽  
Materials Used ◽  
Kaolinitic Clay ◽  
The City ◽  
Mineral Waste

The scheelite occurs mainly in northeastern Brazil, with highest abundance in the states of Rio Grande do Norte and Paraíba - Scheelite Seridó Province. Mining is considered an activity that provides a high environmental degradation due to the large amount of minerals and waste involved. Most mining companies have no technologies or processes that allow the recycling of mineral waste generated. The aim of this study is to evaluate the influence of different percentages of reject on the mechanical properties of scheelite and aesthetic (staining of the final product after firing) of the clay of the city of Boa Saúde - RN. The raw materials used were characterized by XRD, XRF and particle size analysis. Assay was performed by water absorption, linear retraction and bending tests on three points for the characterization of the final product. The raw materials used were from the city of Currais Novos-RN.

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.

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