scholarly journals Synthesis of Blue-Green Phosphors Sr4Si3O8Cl4:Eu2+by Gel-Combustion Method and Their Luminescent Properties

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Yong-Qing Zhai ◽  
Li-Li Wang ◽  
Juan Chen ◽  
Shi-Hua Feng
Keyword(s):  
Broad Band ◽  
Orthorhombic Phase ◽  
Luminescent Properties ◽  
Combustion Method ◽  
Main Peak ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
Gel Combustion ◽  
Main Emission Peak ◽  
Gel Combustion Method

Sr4Si3O8Cl4:Eu2+blue-green phosphors were synthesized by the gel-combustion method. The as-synthesized phosphors were analyzed and characterized by X-ray diffraction and fluorescence spectrophotometer. The results indicate that orthorhombic phaseSr4Si3O8Cl4:Eu2+has been formed after the precursor calcined at 900°C reductive temperature. The excitation spectrum ofSr4Si3O8Cl4:Eu2+is a broad band in the range of 250 ~ 450 nm and the main peak at 324 nm. The emission spectrum is also a broad band with the main emission peak at about 484 nm, which is ascribed to the typical 4f5d1to 4f7transition ofEu2+. Moreover, the effects of the concentration ofEu2+, the reductive temperature, and the doping amount ofMg2+on luminescent properties were discussed.

Effects of Charge Compensators on Structure and Luminescent Properties of Microwave Synthesized CaMoO4:Eu3+ Red Phosphors

2017 ◽  
Vol 727 ◽  
pp. 592-597
Author(s):  
Ying Han ◽  
Zhi Lin Li ◽  
Wan Zhang ◽  
Yan Jie Yin ◽  
Yan Mei Li ◽  
...  
Keyword(s):  
Broad Band ◽  
Luminescent Properties ◽  
Emission Peak ◽  
Luminous Intensity ◽  
Main Peak ◽  
Doping Amount ◽  
X Ray ◽  
Red Phosphors ◽  
Charge Compensator ◽  
Pure Phase

Red phosphors CaMoO4:Eu3+ were synthesized by microwave method with MnO2 as microwave absorbent. The phase structure and luminescent properties of the as-synthesized phosphors were investigated by X-ray powder diffraction and Fluorescence spectrophotometer. The results show that when the reaction time was 40 min, microwave power was medium-high fire (~560 W), we got the tetragonal CaMoO4:Eu3+ pure phase. The excitation spectrum of CaMoO4:Eu3+ was composed by a broad band between 200 nm and 350 nm and a series of peaks from 350 nm to 500 nm. The main peak was at 305 nm. The emission spectrum was composed of a series of peaks in the range of 550~750 nm and the main peak was at 617 nm due to the 5D0→7F2 transition of Eu3+. Doping charge compensator Li+, Na+ or K+ could improve the luminous intensity of the sample. When the doping amount of Li+, Na+ or K+ were 8 mol%, the luminous intensity of the sample reached the maximum. The intensity of the emission peak at 617 nm was 4.04, 3.42, 3.48 times of sample without doping charge compensator.

Synthesis and Luminescence Properties of Blue Phosphors Sr3MgSi2O8:Eu2+ by Gel-Combustion Method

2011 ◽  
Vol 396-398 ◽  
pp. 482-485
Author(s):  
Yong Qing Zhai ◽  
Ya Hong Liu ◽  
Zhi Jiang You ◽  
Jing Qiao ◽  
Man De Qiu
Keyword(s):  
Broad Band ◽  
Combustion Method ◽  
Optimum Process ◽  
Process Conditions ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Gel Combustion ◽  
Reductive Atmosphere ◽  
Two Peaks ◽  
Gel Combustion Method

Blue-emitting phosphors Sr3MgSi2O8:Eu2+ with high brightness were prepared by gel-combustion method under weak reductive atmosphere. The as-synthesized phosphors were investigated by X-ray diffraction analysis (XRD), scanning electron microscope (SEM) and Fluorescence spectrophotometer. The results indicate that Sr3MgSi2O8:Eu2+ phosphors have orthorhombic crystal structure. The excitation spectrum is a broad band and with two peaks at around 414 nm and 400 nm respectively. The emission spectrum is also a broad band, and the emission peak is at about 460 nm. It’s ascribed to typical transition from 4f5d to 4f of Eu2+. Besides, it is found that the dosage of urea, the reductive temperature and time, etc. have great effects on luminescence intensity of Sr3MgSi2O8:Eu2+ phosphors. The optimum process conditions were confirmed.

Synthesis, Characterization and Exploration of Multiferroic Properties in Nano-Crystalline Tb1−x YxMnO3 (0 ≤ x ≤ 0.4)

2016 ◽  
Vol 16 (4) ◽  
pp. 4094-4099 ◽  
Author(s):  
R Shukla ◽  
Keka R Chakraborty ◽  
B.P Mandal ◽  
S. D Kaushik ◽  
M. D Mukadam ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Specific Heat ◽  
Combustion Method ◽  
Magnetic Phase Transitions ◽  
Specific Heat Measurement ◽  
X Ray Diffraction ◽  
Heat Measurement ◽  
Nano Crystalline ◽  
Gel Combustion ◽  
Gel Combustion Method

We report the synthesis and electric properties of nano-crystalline Tb1−xYxMnO3 (x = 0, 0.1, 0.2, 0.3 and 0.4) compounds prepared by gel-combustion method. These samples were characterized by a number of techniques including X-ray diffraction (XRD), Raman spectroscopy, specific-heat measurement, neutron diffraction, and magnetic field dependent pyrocurrent measurement. All the samples crystallize in the orthorhombic structure with space group Pnma at room temperature. Anomalies were observed in low temperature specific-heat measurement corresponding to magnetic and electric phase transitions. The magnetic phase transitions occurred at ∼35, ∼22–28 and ∼7 K for all the samples. Signatures of coupling between magnetic and electric order parameters were revealed by pyrocurrent measurements carried out in presence of magnetic fields.

Synthesis and Luminescent Properties of Ca2Li2BiV3O12:Eu3+ Phosphor

2015 ◽  
Vol 815 ◽  
pp. 309-312
Author(s):  
Si Zhu Chen ◽  
Ke Hui Qiu ◽  
Guo Yin Yan ◽  
Zi Xu Jiang ◽  
Ce Zhao
Keyword(s):  
Solid State ◽  
Broad Band ◽  
Luminescent Properties ◽  
Synthesis Temperature ◽  
Electric Dipole Transition ◽  
Main Peak ◽  
Solid State Method ◽  
Solid State Route ◽  
Good Crystallinity ◽  
Main Emission Peak

A red-emitting phosphor, Eu3+ activated Ca2Li2BiV3O12 was synthesized via combining combustion with solid state method and characterized by X-ray powder diffraction (XRD) and fluorescence spectrophotometer. The influence of synthesis temperature and the concentration of Eu3+ ions, on phase composition and luminescent properties of the synthesized samples was investigated systematically. The results showed that the Ca2Li2BiV3O12:Eu3+ phosphor with high phase purity and good crystallinity can be obtained by this citric acid - assisted sol combustion-solid state route at the synthesis temperature from 600°C to 700°C. The excitation spectrum of Ca2Li2BiV3O12:Eu3+ was composed of a broad band from 200 nm to 385 nm and a number of sharp small peaks extending from 390 nm to 480 nm, and the main peak was at 277 nm. The main emission peak was at 612 nm due to the electric dipole transition of 5D0 → 7F2 of Eu3+, which results in a red emitting. The sample prepared at T=680 °C, Eu3+ mol%=15 mol% has the highest emission intensity in this work.

Electrical and optical properties of SrTiO3 nanopowders: Effect of different dopants Ba and Ag

2016 ◽  
Vol 30 (14) ◽  
pp. 1650207 ◽  
Author(s):  
Mahdi Ghasemifard ◽  
Misagh Ghamari ◽  
Meysam Iziy
Keyword(s):  
Band Gap ◽  
Lattice Structure ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Dielectric Parameters ◽  
Transmission Electron ◽  
Gel Combustion ◽  
Orbital Configuration ◽  
Gel Combustion Method ◽  
Atomic Radii

Using strontium–titanium salts precursor, nanopowders (STO-based-NPs) were successfully synthesized by controlled gel-combustion method. Citric and nitric acids in an optimum ratio were used as the fuel and oxidizer agents, respectively. After heat treatment at 850[Formula: see text]C, the crystalline structure of the products was investigated by X-ray diffraction. The effects of Ba and Ag dopants on particle size distribution were discussed by transmission electron microscopy (TEM). The optical and dielectric parameters such as energy band gap [Formula: see text], real and imaginary parts of refractive index, dielectric function and energy loss function of nanopowders have been investigated by UV–Vis and FTIR spectra. The band gap of SrTiO3 increased with increasing Ba, Ag and Ba–Ag. Different atomic radii of dopants are responsible for changing optical and dielectric parameters due to the altered orbital configuration of the lattice structure.

Perovskite gels combustion synthesis from rare earth aluminates. Development of multifuncional properties.

MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3301-3313
Author(s):  
A. Barrera ◽  
M.L. Chávez ◽  
E. Chavira ◽  
T.A. García ◽  
J.M.E. Carreto
Keyword(s):  
Particle Size ◽  
Rare Earth ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Combustion Method ◽  
Ceramic Pigments ◽  
Material Development ◽  
Gel Combustion ◽  
Gel Combustion Method ◽  
Paramagnetic Properties

AbstractThe purpose of this work was the synthesis of the perovskites with rare earth, by gel combustion method with pigmenting, magnetic and luminescent properties. The synthesis of perovskite structure is important for material development, with multi features. In this work, the synthesis was from metal oxides by the method of combustion of gels at 500 °C, for 10 s. Color of perovskites obtained, with nanometric particle size (31-44 nm) was analysed by CIEL*a*b* with tonalities ranged from white to pink except for Pr-perovskites with yellow and brown. Its paramagnetic properties were verified by magnetic susceptibility. Its luminescence was at 260 nm, except for Pr-perovskites. This work opens an important opportunity to develop ceramic pigments with perovskites structures integrating other properties as luminescence and paramagnetism by combustion sol-gel method.

The Phase Composition of Re3+ (Re=Lu, Gd, La) Co-Doped YAG:Ce and its Luminescent Properties

2010 ◽  
Vol 663-665 ◽  
pp. 129-132 ◽  
Author(s):  
Le Zhang ◽  
Hao Yang ◽  
Peng De Han ◽  
Li Xi Wang ◽  
Qi Tu Zhang
Keyword(s):  
Phase Composition ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Blue Shift ◽  
Combustion Method ◽  
Emission Peak ◽  
Garnet Structure ◽  
Gel Combustion ◽  
Gel Combustion Method ◽  
Co Doped

A series of Re3+ (Re=Lu, Gd, La) co-doped YAG phosphors were successfully synthesized by a sol-gel combustion method and characterized with XRD and photoluminescent spectrum. The phase composition and luminescent properties of YAG:Ce under different Re co-doped concentrations were investigated. Doping only 50 mol% of La3+ to replace Y3+ sites, the main phase of sample has transformed into LaAlO3. While the concentration of Gd3+ reached 90~99 mol%, it was still cubic YAG. Lu3+ could replace Y3+ ions completely with the garnet structure. The location of the emission peak of Gd-codoped YAG:Ce3+ shifted to red region 21 nm corresponding to the maximum emission intensity before the appearance of GdAlO3. In addition, it had a 24 nm blue shift when Y3+ replaced by Lu3+ completely.

scholarly journals Correlation Between Composition and Electrodynamics Properties in Nanocomposites Based on Hard/Soft Ferrimagnetics with Strong Exchange Coupling

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 202 ◽  
Author(s):  
Munirah Abdullah Almessiere ◽  
Alex V. Trukhanov ◽  
Yassine Slimani ◽  
K.Y. You ◽  
Sergei V. Trukhanov ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Sol Gel ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
One Pot ◽  
Linear Behavior ◽  
Gel Combustion ◽  
Pure Exchange ◽  
Strong Exchange ◽  
Gel Combustion Method

In this work, Sr0.3Ba0.4Pb0.3Fe12O19/(CuFe2O4)x (x = 2, 3, 4, and 5) as strongly exchange-coupled nanosized ferrites were fabricated using a one-pot sol–gel combustion method (citrate sol-gel method). The X-ray diffraction (XRD) powder patterns of the products confirmed the occurrence of pure, exchange-coupled ferrites. Frequency dependencies of the microwave characteristics (MW) were investigated using a co-axial method. The non-linear behavior of the MW with the composition transformation may be due to different degrees of Fe ion oxidation on the spinel/hexaferrite grain boundaries and strong exchange coupling during the hard and soft phases.

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