Preparation and Optical Properties of Y2O3:Tb3+ Nanoballs

2016 ◽  
Vol 16 (4) ◽  
pp. 3886-3889 ◽  
Author(s):  
Hongquan Yu ◽  
Ye Qi ◽  
Yanbo Wu ◽  
Jinsu Zhang ◽  
Baojiu Chen
Keyword(s):  
Optimum Concentration ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Particle Sizes ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Homogeneous Precipitation Method ◽  
Scanning Electron Microcopy ◽  
Scanning Electron

Y2O3:Tb3+ nanoballs were synthesized via the urea homogeneous precipitation method (UPM). The resulting Y2O3:Tb3+ phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy, ultraviolet-visible (UV-vis) absorption spectra, and general photoluminescence spectra. The particle sizes estimated using X-ray diffractometry and scanning electron microcopy were about 50–200 nm. The emission intensity of the Y2O3:Tb3+ was low when the doping concentrations of Tb3+ were higher. The optimum concentration of Tb3+ for synthesis of Y2O3:Tb3+ nanocrystals is 1%.

Synthesis of Porous Basic Magnesium Carbonate Crystallographic Materials with Flower-Like Structure

2016 ◽  
Vol 723 ◽  
pp. 444-449 ◽  
Author(s):  
Juan Chen ◽  
Zhi Liang Huang ◽  
Wen Zhao Li
Keyword(s):  
Electron Microscopy ◽  
Magnesium Carbonate ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Experimental Equipment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Homogeneous Precipitation Method ◽  
Chloride Hexahydrate ◽  
Scanning Electron

The porous basic magnesium carbonate (Mg5(CO3)4(OH)2.4H2O) crystal crystallographic materials with flower-like structure were prepared successfully by homogeneous precipitation method. Magnesium chloride hexahydrate (MgCl2.6H2O) and urea (CO(NH2)2) wereused as reaction materials. The experimental equipment was held at 100°C for 8 h. Phase and morphology of the product were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The formation mechanism of the product was investigated. It was found that the CO2 bubbles acted as porous templates. The growth and gathering of the CO2 bubbles induced the growth of the MgCO3.3H2O columnar crystals. Then the dissolution of the MgCO3.3H2O and the deposition of Mg5(CO3)4(OH)2.4H2O happened simultaneously. Finally the disappearance of MgCO3.3H2O brought about the formation of the porous structure.

Synthesis and Characterization of BaCO3 Nanoparticles with Different Morphologies by Microwave Homogenous Precipitation

2013 ◽  
Vol 32 (1) ◽  
pp. 47-50
Author(s):  
Guo Chen ◽  
Jin Chen ◽  
Lijun Liu ◽  
C. Srinivasakannan ◽  
Jinhui Peng
Keyword(s):  
Raw Materials ◽  
Precipitation Method ◽  
Synthesis And Characterization ◽  
Homogeneous Precipitation ◽  
Tetraacetic Acid ◽  
X Ray ◽  
Homogeneous Precipitation Method ◽  
Scanning Electron ◽  
Composition Of Products

AbstractBaCO3 nanoparticles with different morphologies including needle-like, rod-like, bird's nest-like and flower-like have been successfully synthesized by the microwave homogeneous precipitation method using BaCl2·2H2O, NaOH and (NH2)2CO as raw materials with the help of different guide reagents, such as citric acid (CA), sodium triphosphate (STPP) and ethylene diamine tetraacetic acid (EDTA). Their phases and morphologies were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM), respectively. The characterization results show that different guide reagents have little effect on the phase structure and composition of products while they play significant roles in determining the morphology of products. All the synthesized BaCO3 nanoparticles have typical orthorhombic structures that are well-crystallized.

Influence of Synthesis Technics and Additives on Cerium Ion Compound Valence

2011 ◽  
Vol 335-336 ◽  
pp. 1051-1055
Author(s):  
Yan Mei ◽  
Chuan Xia ◽  
Xiao Li Chen ◽  
Zuo Ren Nie
Keyword(s):  
Coupling Method ◽  
Precipitation Method ◽  
Urea Solution ◽  
Homogeneous Precipitation ◽  
State Change ◽  
X Ray Diffraction ◽  
X Ray ◽  
Homogeneous Precipitation Method ◽  
Transmission Electron ◽  
Cerium Ion

In the system of Ce(NO3)3·6H2O and urea solution during homogeneous precipitation method, hydrothermal homogeneous precipitation coupling method and homogeneous precipitation method with additive, X-ray diffraction (XRD) and transmission electron microscope (TEM) were used to study and characterize the product structures and morphologies. The outer electron configurations and the energy conservation theory were used to analyze the reasons for stability of products and valence state change of cerium ions. The results showed that synthesis technics and additives had a great effect on the cerium ion compound valence. The products were orthorhombic Ce2O(CO3)2·H2O with Valence Ш and orthorhombic CeO(CO3)2·H2O with valence Ⅵ by using homogeneous precipitation method and hydrothermal homogeneous precipitation coupling method, respectively. If an additive (triethanolamine or triethylamine) was added into the homogeneous precipitation system, the products changed into a mixture of orthorhombic CeO(CO3)2·H2O with Valence Ⅵ and cubic CeO2 with valence Ⅳ. It showed that triethanolamine or triethylamine had strong oxidizing properties and played a catalyst role in the reaction.

Synthesis and Characterization of Hexagonal Prismatic Ca10(PO4)6(OH)2 Prepared by Homogeneous Precipitation Method

2011 ◽  
Vol 391-392 ◽  
pp. 1239-1243
Author(s):  
Zhan Hui Zhang ◽  
Zhi Liang Huang ◽  
Jian Qiu Li ◽  
Ru An Chi ◽  
Yue Hua Hu ◽  
...  
Keyword(s):  
Growth Process ◽  
Crystal Morphology ◽  
Precipitation Method ◽  
Synthesis And Characterization ◽  
Hexagonal Prism ◽  
Homogeneous Precipitation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Homogeneous Precipitation Method

Hexagonal prismatic hydroxyapatite (Ca10(PO4)6(OH)2, HAP) was successfully prepared by a homogeneous precipitation method. The products were characterized by X-ray diffraction, Fourier transform infrared spectrum, and scanning electron microscope. The growth process of the hexagonal prism was surveyed in detail based on the effects of the reaction time on the phase composition and the crystal morphology.

Synthesis and Characterization of Nanocrystalline Ceria Powder through Homogeneous Precipitation Method

2012 ◽  
Vol 557-559 ◽  
pp. 567-571
Author(s):  
Jin Liang ◽  
Hong Chen
Keyword(s):  
Particle Size ◽  
Orthogonal Experiment ◽  
Fluorite Structure ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Homogeneous Precipitation Method ◽  
Nanocrystalline Ceria

Nanocrystalline ceria powder was prepared through homogeneous precipitation method, orthogonal experiment was designed to figure out the most important factor that influence the particle size of the resultant and the optimum condition. X-ray diffraction revealed that the as-prepared nanoscale ceria powder had cubic fluorite structure, TEM image showed that the ceria powder was weakly agglomerated with a particle size of about 10 nm.

Preparation of α-Ni(OH)2 with Flowerlike Hierarchical Architectures via Homogeneous Precipitation Method

2011 ◽  
Vol 284-286 ◽  
pp. 684-687
Author(s):  
Chang Yu Li ◽  
Li Li Liu ◽  
Shou Xin Liu
Keyword(s):  
Electron Microscopy ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
X Ray ◽  
Homogeneous Precipitation Method ◽  
Α Phase ◽  
Transmission Electron ◽  
Hierarchical Architectures ◽  
Flowerlike Structure ◽  
Adsorption Desorption

Without using any templates or surfactants, flowerlike α-nickel hydroxide (Ni(OH)2) was successfully synthesized by homogeneous precipitation method. The prepared products were characterized by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and N2 adsorption-desorption. The prepared Ni(OH)2 is α-phase with specific surface area of 245.0 m2/g and shows flowerlike structure with 4-6 um in diameter.

Synthesis of Visible-Light Responsive CdS/ZnO Nanocomposite Photocatalysts via Simple Precipitation Method

2014 ◽  
Vol 608 ◽  
pp. 224-229 ◽  
Author(s):  
Potjanaporn Chaengchawi ◽  
Karn Serivalsatit ◽  
Pornapa Sujaridworakun
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Precipitation Method ◽  
Cds Nanoparticles ◽  
Methylene Blue Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Blue Solution ◽  
Scanning Electron

A visible-light responsive CdS/ZnO nanocomposite photocatalyst was successfully synthesized by precipitation of CdS nanoparticles, using Cd (NO3)2 and Na2S as starting materials, on ZnO nanoparticles and then calcined at 400°C for 2 hours. The effects of the mole ratio of CdS and ZnO in the composites on their phase, morphology, and surface area were investigated by X-ray Diffraction (XRD), scanning electron microscope (SEM), Brunauer Emmett Teller method (BET), respectively. The photocatalytic degradation of methylene blue solution in the presence of composite products under visible-light irradiation was investigated. The results showed that the mole ratio of CdS and ZnO played a significant role on photocatalytic performance. The highest photocatalytic activity was obtained from the CdS/ZnO nanocomposite with mole ratio of 1:4, which is higher than that of pure CdS and pure ZnO.

scholarly journals A Novel Strong Cyan Luminescence Emission of Tb2O3 Particles

2021 ◽  
Author(s):  
Fatma Unal
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ammonium Carbonate ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Terbium Oxide ◽  
X Ray ◽  
Ft Ir ◽  
Pl Emission ◽  
Scanning Electron

Abstract Terbium oxide (Tb2O3) particles (NPs) were synthesized by precipitation method using ammonium carbonate as precipitation agent. Effects of precursor molarity (0.1, 0.15 and 0.2 M) on photoluminescence (PL) behaviour of the NPs were investigated. The presence of the Tb2O3 phase was confirmed by X-Ray Diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) analyses. Morphological investigations of the produced powders were made by Field Emission Gun-Scanning Electron Microscopy (FEG-SEM). It showed that the morphology of Tb2O3 particles transformed from the nanograin chain to bundles morphology of rod-like as the amount of precursor molarity increased. Emission spectrum were investigated by Photoluminescence (PL) Spectroscopy. All the Tb2O3 particles exhibited the strongest peak at 493 nm ascribed to 5D4-7F6 (magnetic dipole (MD), C2) transition. The increase in the number of C2 sites released from the MD transition with the increase of the precursor molarity caused a negative increase in the b* (yellowness/blueness of the emission) value in the CIE diagram, indicating that the colour shifted to the blue region. The Tb2O3 particles produced by the precipitation method exhibited novel strong cyan colour and the PL emission intensity increased with increasing molarity.

scholarly journals Synthesis and characterization of apatite silicated powders with wet precipitation method

2021 ◽  
Vol 234 ◽  
pp. 00106
Author(s):  
Houda Labjar ◽  
Hassan Chaair
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Analytical Techniques ◽  
Precipitation Method ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wet Precipitation ◽  
Scanning Electron

The synthesis of apatite silicated Ca10(PO4)6-x(SiO4)x(OH)2-x (SiHA) with 0≤x≤2 was investigated using a wet precipitation method followed by heat treatment using calcium carbonate CaCO3 and phosphoric acid H3PO4 and silicon tetraacetate SiC8H20O4 (TEOS) in medium of water ethanol, with three different silicate concentrations. After drying, the samples are ground and then characterized by different analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron Microscopy (SEM) and chemical analysis.

Microstructure and Properties of Nanosemicrystalline Si3N4 Ceramics with Doped Sintering Additives: Part II. Phase Transformation and Microstructural Control

1998 ◽  
Vol 13 (9) ◽  
pp. 2588-2596 ◽  
Author(s):  
K. H. Ryu ◽  
J-M. Yang
Keyword(s):  
Electron Microscopy ◽  
Pressureless Sintering ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Additives ◽  
Different Temperatures ◽  
Si3n4 Ceramics ◽  
Scanning Electron ◽  
Microstructural Control

The low temperature pressureless sintering of a nanosized Si3N4 powder with doped sintering additives was investigated. The microstructural evolution during sintering at different temperatures was analyzed using x-ray diffraction and scanning electron microscopy. The effect of using nanosized Si3N4 powder as a catalyst to accelerate the α→β–Si3N4 transformation of a commercial Si3N4 powder with larger particle sizes was also investigated. Finally, two stage sintering was used to study the feasibility of controlling the microstructure and the mechanical properties of the nanosized silicon nitride.

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