Photoluminescence Properties of NaLa(WO4)2:Tb3+ Novel Green Phosphors Prepared by the Combustion Method

2011 ◽  
Vol 694 ◽  
pp. 513-517 ◽  
Author(s):  
Xian Hua Qian ◽  
Xi Peng Pu ◽  
Da Feng Zhang ◽  
Shi Cai Cui ◽  
Yan Yan Gao
Keyword(s):  
Green Light ◽  
Combustion Method ◽  
Impurity Phase ◽  
Optimum Concentration ◽  
Optimum Temperature ◽  
Excitation Band ◽  
Photoluminescence Properties ◽  
Wide Region ◽  
X Ray ◽  
Light Excitation

A series of NaLa(WO4)2:Tb3+ green phosphors have been prepared by a facile combustion method. X-ray powder diffraction (XRD) and photoluminescence were used to characterize the structure and luminescence properties of as-synthesized phosphors, respectively. The XRD results confirm that the as-synthesized phosphors exhibit sheelite-type structure without any impurity phase. The excitation band of the phosphors covers a wide region of 200-300 nm. The as-obtained phosphors emit strong green light centered at 546 nm under ultraviolet light excitation (261 nm). The results show that the optimum temperature is 800°C and the optimum concentration of Tb3+-dopant is 50 at%.

Combustion Synthesis and Luminescence Properties of NaY1-XTbX(WO4)2 Novel Green Phosphors

2011 ◽  
Vol 295-297 ◽  
pp. 861-864
Author(s):  
Xian Hua Qian ◽  
Da Feng Zhang ◽  
Xi Peng Pu
Keyword(s):  
Decay Curve ◽  
Green Light ◽  
Combustion Method ◽  
Luminescence Properties ◽  
Photoluminescence Spectra ◽  
Green Phosphor ◽  
X Ray ◽  
Fluorescent Lamps ◽  
Structure Morphology ◽  
Light Excitation

NaY1-xTbx(WO4)2 green phosphors have been synthesized by a facile combustion method. The structure, morphology and luminescence properties of as-synthesized phosphors were characterized via X-ray powder diffraction (XRD), photoluminescence spectra, and decay curve. The XRD results indicate that as-synthesized phosphors exhibit sheelite-type structure without any impurity phase. The as-obtained phosphors emit strong green light centered at 546 nm under ultraviolet light excitation. The lifetimes are about 0.57 ms. The excellent luminescence properties make it a new promising green phosphor for fluorescent lamps application.

Fabrication and Sinter-Ability of Ce3+-Doped YAG Ceramics by Low-Temperature Combustion Method

2011 ◽  
Vol 299-300 ◽  
pp. 493-497
Author(s):  
Zhi Qiang Wang ◽  
Xin Sun ◽  
Xiao Li Zhou
Keyword(s):  
Low Temperature ◽  
Sintering Temperature ◽  
Combustion Method ◽  
Linear Shrinkage ◽  
Raw Material ◽  
Low Temperature Combustion ◽  
Photoluminescence Properties ◽  
X Ray ◽  
Sintering Additive ◽  
Temperature Combustion

The phosphors YAG doped with Ce3+was prepared by low-temperature combustion method. Utilizing the prepared YAG powders as raw material and Li2O-CaO-ZnO-Y2O3-Al2O3-SiO2glass powder as sintering additive, YAG:Ce3+ceramics were sintered at 1400-1550°C for 10h in vacuum. Thesinter-ability of the YAG ceramics was studied by measuring the linear shrinkage rate. The phase, microstructure and photoluminescence properties of the YAG: Ce3+powders and ceramics were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) analysis. The results show that the sinter-ability properties of YAG:Ce3+ceramics was mainly associated with sintering temperature and contents of glass sintering additive; the best result was achieved when the sample was sintered at 1500°C and doped sintering additive of 1%.

Influence of S⁄La Molar Ratio on the Morphology and Optical Property of La2S3 Microcrystalline Prepared by Microwave Hydrothermal

2012 ◽  
Vol 512-515 ◽  
pp. 223-226
Author(s):  
Ye Zhang ◽  
Li Yun Cao ◽  
Jian Feng Huang ◽  
Jian Peng Wu
Keyword(s):  
Ultraviolet Light ◽  
Room Temperature ◽  
Molar Ratio ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Microwave Hydrothermal ◽  
Irregular Shapes ◽  
Light Excitation

The La2S3 microcrystalline were prepared by microwave hydrothermal method (M–H). The influences of different S⁄La molar ratio on the phase composition, and morphology of the La2S3 microcrystalline were particularly investigated. The obtained samples were characterized by X–ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet and visible–spectroscopy (UV–vis) and photoluminescence spectroscopy (PL) at room temperature. XRD results show that the decrease of S⁄La molar ratio from 6⁄3 to 6⁄6, the improving in crystallization of the obtained microcrystalline is observed with the decrease in S⁄La molar ratio. The morphology of prepared La2S3 transforms from irregular shapes to quasi-sphere structure. The as-prepared microcrystalline show excellent absorbency of ultraviolet light and are almost transparent to visible light to exhibit stable violet-blue photoluminescence properties under the ultraviolet light excitation at room temperature.

SYNTHESIS AND PHOTOLUMINESCENCE PROPERTIES OF Er3+, Eu3+ IONS ACTIVATED SrAl12O19

2006 ◽  
Vol 20 (29) ◽  
pp. 4891-4898 ◽  
Author(s):  
VIJAY SINGH ◽  
JUN-JIE ZHU
Keyword(s):  
Optical Properties ◽  
Combustion Method ◽  
Photoluminescence Spectra ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminate Phosphor

Synthesis of Er 3+, Eu 3+ ions activated strontium hexa-aluminate phosphor using the combustion method is described. An efficient phosphor can be prepared by this method at reaction temperatures as low as 500°C in a few minutes. Powder X-ray diffraction and the optical properties were studied by photoluminescence spectra.

scholarly journals PENGARUH SUHU PADA PEMBENTUKAN PRECIPITATED CALCIUM CARBONATE (PCC) MELALUI METODA KAUSTIK SODA DENGAN MENGGUNAKAN PELARUT ASAM KLORIDA

2015 ◽  
Vol 3 (1) ◽  
pp. 12
Author(s):  
Budi Hermawan ◽  
Syukri Arief ◽  
Novesar Jamarun
Keyword(s):  
Electron Microscopy ◽  
Calcium Carbonate ◽  
Optimum Concentration ◽  
The Other ◽  
Optimum Temperature ◽  
X Ray Diffraction ◽  
Precipitated Calcium Carbonate ◽  
X Ray ◽  
The One ◽  
Scanning Electron

 ABSTRACT Precipitated Calcium Carbonate (PCC) is the limestone product resulting from certain process steps. By XRF measurement it has found that the content of CaO (oxide calcium) in limestone Bukit Tui Padang Panjang as follows 54.19%, SiO2 1.03%, Al2O3 0.39%, MgO 0.46% and Fe2O3 0.2%. Rendemen PCC at optimum concentration of 0.75 M HCl is 69.77%. The formation of PCC by using the highest PCC rendemen aquabides is 9.28% at optimum temperature of 50°C. With 0.75 M HCl, the highest rendemen is 79.32% at optimum temperature 70°C. The formation of crystals in the form vaterite, aragonite and calcite were evidenced by X-ray Diffraction (XRD). Treatment with 2.00 M HCl at 30°C showed the formation of vaterite (45.83%), aragonite (35.93%) and calcite (18.24%) with crystals size of 28.43 nm. In the other case, preparation with 0.75 M HCl at 30°C resulting the percentage of vaterite and aragonite which were 73.01% and 26.99% respectively fairished 28.06 nm. Then for the one which were treated with 0.75 M HCl at 70°C indicated the formation of vaterite (75.53%) fairished 33.68 nm and aragonite (24.47%). SEM (Scanning Electron Microscopy) towards the sample prepared from 0.75 M HCl at 30°C have clearly shown that the particle sphere fairished at 3.68 nm where the one treated with 0.75 M HCl at 70°C having particle sphere fairished at 3.3 µm showing needle like estimated of 3.8 µm. Keywords : Precipitated Calcium Carbonate (PCC), caustic soda method 

Role of Sm3+ Doping on Structural, Optical and Photoluminescence Properties of ZnO Nanoparticles Synthesized by Sol-gel Auto- combustion Method

2020 ◽  
Vol 5 (3) ◽  
pp. 236-251
Author(s):  
Eshwara I. Naik ◽  
Halehatty S.B. Naik ◽  
Ranganaik Viswanath
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Combustion Method ◽  
Content Increase ◽  
Photoluminescence Properties ◽  
Tem Analysis ◽  
Auto Combustion ◽  
Ion Doping ◽  
Doped Zno ◽  
Pl Intensity

Background: Various interesting consequences are reported on structural, optical, and photoluminescence properties of Zn1-xSmxO (x=0, 0.01, 0.03 and 0.05) nanoparticles synthesized by sol-gel auto-combustion route. Objective: This study aimed to examine the effects of Sm3+-doping on structural and photoluminescence properties of ZnO nanoparticles. Methods: Zn1-xSmxO (x=0, 0.01, 0.03 and 0.05) nanoparticles were synthesized by sol-gel auto combustion method. Results: XRD patterns confirmed the Sm3+ ion substitution through the undisturbed wurtzite structure of ZnO. The crystallite size was decreased from 24.33 to 18.46 nm with Sm3+ doping. The hexagonal and spherical morphology of nanoparticles was confirmed by TEM analysis. UV-visible studies showed that Sm3+ ion doping improved the visible light absorption capacity of Sm3+ iondoped ZnO nanoparticles. PL spectra of Sm3+ ion-doped ZnO nanoparticles showed an orange-red emission peak corresponding to 4G5/2→6HJ (J=7/2, 9/2 and 11/2) transition of Sm3+ ion. Sm3+ ion-induced PL was proposed with a substantial increase in PL intensity with a blue shift in peak upon Sm3+ content increase. Conclusion: Absorption peaks associated with doped ZnO nanoparticles were moved to a longer wavelength side compared to ZnO, with bandgap declines when Sm3+ ions concentration was increased. PL studies concluded that ZnO emission properties could be tuned in the red region along with the existence of blue peaks upon Sm3+ ion doping, which also results in enhancing the PL intensity. These latest properties related to Sm3+ ion-doped nanoparticles prepared by a cost-efficient process appear to be interesting in the field of optoelectronic applications, which makes them a prominent candidate in the form of red light-emitting diodes.

scholarly journals Y3+ substituted Sr-hexaferrites: sol-gel synthesis, structural, magnetic and electrical characterization

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 274-281 ◽  
Author(s):  
S. S. Satpute ◽  
S. R. Wadgane ◽  
S. R. Kadam ◽  
D. R. Mane ◽  
R. H. Kadam
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Combustion Method ◽  
Hexagonal Structure ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
Auto Combustion

Abstract Y3+ substituted strontium hexaferrites having chemical composition SrYxFe12-xO19 (x= 0.0, 0.5, 1.0, 1.5) were successfully synthesized by sol-gel auto-combustion method. The structural and morphological studies of prepared samples were investigated by using X-ray diffraction technique, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy. The X-ray diffraction pattern confirmed the single-phase hexagonal structure of yttrium substituted strontium ferrite and the lattice parameters a and c increased with the substitution of Y3+ ions. The crystallite size also varied with x content from 60 to 80 nm. The morphology was studied by FE-SEM, and the grain size of nanoparticles ranged from 44 to 130 nm. The magnetic properties were investigated by using vibrating sample magnetometer. The value of saturation magnetization decreased from 49.60 to 35.40 emu/g. The dielectric constant decreased non-linearly whereas the electrical dc resistivity increased with the yttrium concentration in strontium hexaferrite.

scholarly journals Efficient Removal of Levofloxacin by Activated Persulfate with Magnetic CuFe2O4/MMT-k10 Nanocomposite: Characterization, Response Surface Methodology, and Degradation Mechanism

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3583
Author(s):  
Junying Yang ◽  
Minye Huang ◽  
Shengsen Wang ◽  
Xiaoyun Mao ◽  
Yueming Hu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Photoelectron Spectroscopy ◽  
Degradation Mechanism ◽  
Sol Gel ◽  
Combustion Method ◽  
Copper Ferrite ◽  
X Ray ◽  
Rsm Model

In this study, a magnetic copper ferrite/montmorillonite-k10 nanocomposite (CuFe2O4/MMT-k10) was successfully fabricated by a simple sol-gel combustion method and was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the Brunner–Emmett–Teller (BET) method, vibrating sample magnetometer (VSM), and X-ray photoelectron spectroscopy (XPS). For levofloxacin (LVF) degradation, CuFe2O4/MMT-k10 was utilized to activate persulfate (PS). Due to the relative high adsorption capacity of CuFe2O4/MMT-k10, the adsorption feature was considered an enhancement of LVF degradation. In addition, the response surface methodology (RSM) model was established with the parameters of pH, temperature, PS dosage, and CuFe2O4/MMT-k10 dosage as the independent variables to obtain the optimal response for LVF degradation. In cycle experiments, we identified the good stability and reusability of CuFe2O4/MMT-k10. We proposed a potential mechanism of CuFe2O4/MMT-k10 activating PS through free radical quenching tests and XPS analysis. These results reveal that CuFe2O4/MMT-k10 nanocomposite could activate the persulfate, which is an efficient technique for LVF degradation in water.

scholarly journals Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi
Keyword(s):  
Magnetic Properties ◽  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Combustion Method ◽  
Lemon Juice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

scholarly journals Microwave-Assisted Combustion Synthesis of ZnO Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
M. Kooti ◽  
A. Naghdi Sedeh
Keyword(s):  
Electron Microscopy ◽  
Zno Nanoparticles ◽  
Combustion Method ◽  
Zinc Nitrate ◽  
High Yield ◽  
Fast Method ◽  
Simple Method ◽  
X Ray ◽  
Microwave Assisted ◽  
Average Size

A new and simple method was applied for the synthesis of ZnO nanoparticles with an average size of 20 nm. In this microwave-assisted combustion method, glycine as a fuel and zinc nitrate as precursor were used. The final product was obtained very fast with high yield and purity. The synthesized nanoscale ZnO was characterized by X-ray Diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FT-IR). The size and morphology of the ZnO nanoparticles have been determined by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. This is a simple and fast method for the preparation of ZnO nanoparticles with no need for expensive materials or complicated treatments.

Sign in / Sign up

Export Citation Format

Share Document