Combustion Synthesis of Nanocrystalline Y2O2S: Eu 3+ , Mg 2+ , Ti 4+ Red Long-Lasting Phosphors Using Mixture Fuel of Thiourea and Citric Acid

2013 ◽  
Vol 652-654 ◽  
pp. 669-672 ◽  
Author(s):  
Xiao Bao Han ◽  
Xiang Guo Li ◽  
Gui Hua Peng ◽  
Zhen Hua Liang ◽  
Xia Wang
Keyword(s):  
Citric Acid ◽  
Luminescent Properties ◽  
Combustion Method ◽  
Molar Ratio ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
Red Emission ◽  
X Ray ◽  
Structure Morphology

Nanocrystalline Y2O2S: Eu3+, Mg2+, Ti4+red long-lasting phosphor was synthesized successfully by combustion method using thiourea and citric acid as fuel. The structure, morphology and luminescent properties of these phosphors were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL). The experimental results revealed that the phosphor was composed of sheet-shaped Y2O2S with hexagonal crystal structure. They exhibited strong red emission at 617 nm and 626nm. In addition, the dosage of citric acid has great effect on the phosphor. When molar ratio of citric acid to Y3+is 1.3, the resulted phosphor gives the highest emission intensity.

scholarly journals New Ternary Compounds of the Composition Cu2SnTi3 and Their Crystal Structures

2020 ◽  
Vol 10 (24) ◽  
pp. 8776
Author(s):  
Sheng-Fang Huang ◽  
Yen-Cheng Chang ◽  
Po-Liang Liu
Keyword(s):  
Crystal Structure ◽  
Total Energy ◽  
Ternary Compound ◽  
Density Functional ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
Orthorhombic Crystal Structure ◽  
X Ray ◽  
Atomic Structures

A new ternary compound Cu2SnTi3 has been synthesized by vacuum sintering at 900 °C. The atomic structures of CaCu5- and InNi2-like Cu2SnTi3 are calculated using density functional theory methods. The X-ray diffraction (XRD) analysis and selected area diffraction (SAD) patterns of the new ternary compound Cu2SnTi3 are considered to verify the atomic structures of CaCu5- and InNi2-like Cu2SnTi3. The results reveal that the InNi2-like Cu2SnTi3 model has the lowest total energy of −35.239 eV, representing the trigonal crystal structure. The orthorhombic crystal structure of the CaCu5-like Cu2SnTi3 model has the second lowest total energy of −33.926 eV. Our theoretical X-ray diffraction peak profiles of InNi2-like (CaCu5-like) Cu2SnTi3 are nearly identical to experimental one, leading to an error below 2.0% (3.0%). In addition, the hexagonal crystal structure of the CaCu5-like Cu2SnTi3 model has the highest total energy of −33.094 eV. The stability of the Cu2SnTi3 in terms of energy follows the order: the trigonal, orthorhombic, and hexagonal crystal structure.

Characterization of Zn0.96Al0.02Ga0.02O Thermoelectric Material

2013 ◽  
Vol 802 ◽  
pp. 227-231
Author(s):  
Panida Pilasuta ◽  
Pennapa Muthitamongkol ◽  
Chanchana Thanachayanont ◽  
Tosawat Seetawan
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Single Phase ◽  
Hexagonal Structure ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
X Ray ◽  
Transmission Electron

Crystal structure of Zn0.96Al0.02Ga0.02O was analyzed by X-Ray diffraction (XRD) technique and the microstructure was observed by scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD results showed single phase and hexagonal structure a = b = 3.24982 Å, and c = 5.20661 Å. The SEM and TEM results showed the grain size of material arrangement changed after sintering and TEM diffraction pattern confirmed hexagonal crystal structure of Zn0.96Al0.02Ga0.02O after sintering.

Luminescent Properties of Ca1-xBaxSnO3: Eu3+, Dy3+ Composites Prepared by Coprecipitation

2014 ◽  
Vol 989-994 ◽  
pp. 383-386
Author(s):  
Li Min Dong ◽  
Fei Lv ◽  
Qin Li ◽  
Zhi Dong Han ◽  
Xian You Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fluorescence Spectroscopy ◽  
Emission Intensity ◽  
Luminescent Properties ◽  
Emission Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Scanning Electron

A series of Eu3+, Dy3+ actived Ca1-xBaxSnO3 phosphors were synthesized by coprecipitation method. The structure, morphology and fluorescence property of phosphors were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectroscopy. SEM results showed that the as-prepared phosphors are smooth and uniform with the cubic morphology. The incorporation of a small amount of Ba to CaBaSnO3 improved the emission characteristics. Fluorescence spectrum showed the emission intensity is the best with the incorporation of Ba2+ (x = 0.3), when calcination temperature is 900°C.

A Modified Hydrothermal Synthesis and Luminescence of Hydroxyapatite Doped with Ce3+ and Tb3+ Ions

2013 ◽  
Vol 750-752 ◽  
pp. 1639-1642
Author(s):  
Si Hua Wang ◽  
Zhi Gang Liu ◽  
Qiao Wang ◽  
Li Rong Yang ◽  
Feng Feng Li ◽  
...  
Keyword(s):  
Lattice Structure ◽  
Hydrothermal Process ◽  
Hexagonal Lattice ◽  
Luminescent Properties ◽  
Emission Lines ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dispersed Particles ◽  
Structure Morphology ◽  
Small Change

Luminescent Ln3+ (Ce3+, Tb3+) doped hydroxyapatite (HAp: Ce, Tb) phosphors were successfully fabricated via the modified hydrothermal process. The structure, morphology, and luminescent properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectra respectively. The XRD results reveal that the obtained HAp: Ce, Tb phosphors show the characteristic peaks of hydroxyapatite in a hexagonal lattice structure and the import of Ce3+and Tb3+ causes small change in the crystalline structure and leads to the peaks shifting and declining. It is observed that the as-prepared luminescent samples exhibit nearly equiaxial morphology of dispersed particles about 50-150 nm in size. Under 254 nm UV radiation excitation, the phosphors demonstrate the characteristic 5D47F36 emission lines of Tb3+and the excitation of Tb3+ is mainly caused by the energy transfer from Ce3+. PL intensity of Tb3+ doped HAp remarkably strengthened with increment of Ce3+ concentration and reached the maximum at the concentration of 4 mol%.

Halogen-Elpasolithe, IV [1]. Über Brom-Elpasolithe Cs2BIMIIIBr6 BI = Li, Na; MIII = Sc, Y, La-Lu, In, V, Cr) / Halo-Elpasolites, IV [1]. On Bromo-Elpasolites Cs2BIMIIIBr6 BI = Li, Na; MIII = Sc, Y, La-Lu, In, V, Cr)

1978 ◽  
Vol 33 (12) ◽  
pp. 1476-1478 ◽  
Author(s):  
Gerd Meyer ◽  
Hans-Christian Gaebell
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
X Ray

Bromo-Elpasolites of formulae Cs2LiMBr6 and Cs2NaMBr6 (M = Sc, Y, La-Lu, In, V, Cr) were prepared and investigated by powder X-ray diffraction. The compounds Cs2NaMBr6 (M = Ce-Lu, Sc, Y, In) as well as Cs2LiMBr6 (M = La-Er, Y) crystallize cubic facecentered (elpasolite type of structure); Cs2NaLaBr6 and low temperature forms of Cs2NaMBr6 (M = Ce-Gd) are tetragonal. Several hexagonal crystal structure types (HT-K2LiAlF6, Cs2NaCrF6, Cs2LiGaF6) are observed for Cs2LiMBr6 (M = Tm, Yb, Lu, Sc, In, V, Cr).

Photoluminescent Characteristics of ZnS Quantum Dots Synthesized in Non-Aqueous-Phase

2013 ◽  
Vol 750-752 ◽  
pp. 991-994
Author(s):  
Jing Liu ◽  
Ming Ying ◽  
Yu Ling Tan ◽  
Bo Xi
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Quantum Yield ◽  
Reaction Medium ◽  
Emission Spectra ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Zinc Blend ◽  
Red Emission ◽  
X Ray

ZnS quantum dots (ZnS QDs) synthesized in aqueous solution is easy to gather a mass, which always results in low quantum yield. So, in this study benzene was used as reaction medium in which ZnS QDs with different hues were synthesized, and the hues of ZnS QDs were depend on the molar ratio of Zn (CH3COO)2 and Na2S·9H2O. The results show the emission spectra of ZnS QDs shifts with the change of the precursor molar ratio but the absorption peak at 310nm is not. The emission peaks centered at 430nm and 580nm at higher molar ratio [Zn2+]/[S2-] with blue-violet emitting phosphors; but, ZnS QDs synthesized at higher molar ratio [S2-]/[Zn2+] have orange-red emission at 580nm only. The X-ray diffraction analysis shows the crystallinity of ZnS QDs is better at [Zn2+]/[S2-]=1:10, which are typical zinc blend with nanorod structure.

Crystal Structure and Luminescent Properties of Complex [Eu0.5Gd0.5(C12H9O2)2(C12H8N2)2(H2O)2]•(C12H9O2)•H2O

2012 ◽  
Vol 554-556 ◽  
pp. 691-694
Author(s):  
Hai Tao Xia ◽  
Yu Fen Liu ◽  
De Fu Rong
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Ternary Complex ◽  
Luminescent Properties ◽  
Luminescence Spectra ◽  
X Ray Diffraction ◽  
Red Emission ◽  
X Ray ◽  
Sharp Band ◽  
Complex Display

One new rare-earth ternary complex with 1-naphthylacetic acid and 1,10-phenanthroline, [Eu0.5Gd0.5(C12H9O2)2(C12H8N2)2(H2O)2]•(C12H9O2)•H2O were synthesized. The structures were established by single crystal X-ray diffraction. The europium (gadolinium) ion is eight-coordinate with four oxygen and four nitrogen atoms forming a coordination polyhedron best describable as a distorted dodecahedral. The luminescence spectra of the complex in a solution of DMF were studied. The complex display characteristic Eu(III)-originated red emission as a sharp band at 617 nm. It is concluded that the metal-centered red emission is promoted by the ligand-assisted energy transfer.

Cerium Oxygen Apatite (Ce4.67[SiO4]3O) X-Ray Diffraction Pattern Revisited

1992 ◽  
Vol 7 (4) ◽  
pp. 219-222 ◽  
Author(s):  
A. Cuneyt Tas ◽  
Mufit Akinc
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Diffraction Pattern ◽  
Solid State Reaction ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
X Ray ◽  
Lattice Constants ◽  
Close Resemblance

AbstractA new X-ray diffraction pattern for the compound cerium oxygen apatite, Ce4.67[SiO4]3O is suggested. The compound was prepared by the solid state reaction of the oxides, CeO2 and SiO2 and has a hexagonal crystal structure with the lattice constants a = 9.6578 Å and c = 7.1187 Å. The sample of the most recent PDF pattern 31-0336* (Visser, 1978) for this compound is believed to be contaminated with significant quantities of N owing to the fact that it was prepared by mixing Ce2O3 and Si3N4 and its very close resemblance to the pattern displayed in the PDF 33-0333 given for the cerium “nitrogen” apatite, Ce5[SiO4]3N.

scholarly journals Morphology and Photoluminescence of Ba0.5Sr0.5MoO4Powders by a Molten Salt Method

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ling Wei ◽  
Yunfei Liu ◽  
Yinong Lu ◽  
Tao Wu
Keyword(s):  
Molten Salt ◽  
Great Influence ◽  
Emission Peak ◽  
Molar Ratio ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
Soaking Time ◽  
X Ray ◽  
Structure Morphology ◽  
Phase Size

Ba0.5Sr0.5MoO4powders with scheelite-type tetragonal structure were successfully synthesized by a molten salt method. The structure, morphology, and luminescent property of the as-prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL), respectively. The results show that the tetragonal Ba0.5Sr0.5MoO4powders were synthesized at 650°C for 6 h by the molten salt method. The calcining temperature, the soaking time, and the molar ratio of the salt to Na2MoO4have great influence on the phase, size, morphology, and PL properties. The better crystallinity and smaller particle size, the higher PL emission peak is.

Oxidfluoridsulfide der Lanthanoide vom Formeltyp M3OF5S (M = Nd, Sm, Gd–Ho) / Oxide Fluoride Sulfides of the Lanthanoids with the Formula M3OF5S (M = Nd, Sm, Gd–Ho)

2011 ◽  
Vol 66 (3) ◽  
pp. 213-220
Author(s):  
Hagen Grossholz ◽  
Oliver Janka ◽  
Thomas Schleid
Keyword(s):  
Crystal Structure ◽  
Electron Beam ◽  
Single Crystal ◽  
The Other ◽  
Molar Ratio ◽  
Hexagonal Crystal Structure ◽  
Hexagonal Crystal ◽  
X Ray ◽  
Phase Pure ◽  
Trigonal Prismatic

First attempts to synthesize a lanthanoid(III) oxide fluoride sulfide were successful by reacting DyF3 and Dy2O3 with dysprosium and sulfur in a 2 : 5 : 1 : 3 molar ratio at 850 ◦C in tightly sealed tantalum ampoules. In analogy to the dysprosium compound Dy3OF5S, the other representatives of the M3OF5S series with M = Nd, Sm, Gd-Ho could be prepared as well. Almost phase-pure samples were obtained under similar flux-assisted (NaCl) conditions according to 2M +5MF3 +M2O3 + 3S →3M3OF5S. In the hexagonal crystal structure (space group: P63/m; a ≈ 961 - 939 pm, c ≈ 378 - 367 pm; c/a≈0.39,Vm ≈91 - 84 cm3 mol−1, Z = 2), the M3+ cations reside in ninefold anionic coordination realized as tricapped trigonal prisms formed by seven light (O2−/F−) and two heavier S2− anions. One light-anion position exhibits the exclusive character of F− in trigonal non-planar coordination (CN = 3), while the other position with a tetrahedral cationic environment (CN = 4) is mixed occupied by F− and O2− in a 2 : 1 ratio. The S2− anions are coordinated in a trigonal prismatic way by six M3+ cations. From the data of single-crystal X-ray structure analyses, no indication of any ordering for the O2− and F− anions could be obtained, but bond-valence and MAPLE calculations confirmed the results of electron-beam microanalyses carried out earlier to reveal ordered models for Dy3OF5S.

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