Luminescence properties of Eu2+ and Sm3+ co-doped in KBaPO4

2021 ◽  
Vol 40 (1) ◽  
pp. 389-396
Author(s):  
Yingwei Xu ◽  
Tingting Zhang ◽  
Li Zheng ◽  
Ailing Zou
Keyword(s):  
Solid Phase ◽  
Xrd Analysis ◽  
Rare Earth Ions ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Fluorescence Measurements ◽  
Xrd Patterns ◽  
Co Doped

Abstract KBaPO4:Eu2+/Sm3+ phosphor was synthesized via the high-temperature solid-phase reaction method. The structural properties, surface morphology, and optical properties of the synthesized samples were obtained by the X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and fluorescence measurements. The XRD patterns indicate that the crystal structure of KBaPO4 has not been changed by co-doped with two rare-earth ions. Under the excitation of 400 nm, the Eu2+ and Sm3+ co-doped KBaPO4 phosphors showed typical emission peaks at 430 (blue), 562 (yellow), and 600 nm (red). Meanwhile, with the increase of the Sm3+ content, the photoluminescent (PL) emission intensity of Sm3+ increased until the content reaches 0.12. However, the PL intensity of Eu2+ ions gradually decreased, which indicated that there was a possible energy transfer between the two ions. Therefore, the obtained results indicated that Eu2+/Sm3+ co-doped KBaPO4 is a promising phosphor for the use in white light-emitting diodes with near ultraviolet chips.

Fabrication of Lithium Silicate Doped with Lithium Titanate by Solid-State Reaction and its XRD Study

2012 ◽  
Vol 624 ◽  
pp. 200-203
Author(s):  
Yu Tian Wang ◽  
You Dong Cao ◽  
Jin Hu ◽  
Wei Jun Zhang ◽  
Da Ping Wu ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Solid Phase ◽  
Raw Materials ◽  
Xrd Analysis ◽  
Lithium Titanate ◽  
Lithium Silicate ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Scanning Calorimetry

Fabrication of lithium silicate powder containing lithium titanate by solid phase reaction method. LiFabrication of lithium silicate powder doped with lithium titanate by solid-state reaction. Take lithium carbonate, silicon dioxide and titania as raw materials and then these powders were mixed according to the different ratios and grinded in an agate mortar for 15 min. And then the mixture were dried at 80°C. Finally, the samples were sintered in vacuum tube furnace at 750, 800, 850 and 900°C for 2h. Thermogravimetric analysis, differential scanning calorimetry and XRD analysis were carried out systematically in this paper. The reaction process and mechanism at different temperatures and the effect of the different ratios and sintering temperature were discussed. Experimental results showed that lithium titanate component increased with increasing amount of titanium dioxide. While the mixture were sintered at 900°C for 2h, there would have lithium silicate and lithium titanate phase.

Bifunctional application of La3BWO9:Bi3+, Sm3+ phosphors with strong orange-red emission and sensitive temperature sensing properties

2021 ◽  
Author(s):  
Weiguang Ran ◽  
Guangshi Sun ◽  
Xiaoli Ma ◽  
Liyun Zhang ◽  
Jae Su Yu ◽  
...  
Keyword(s):  
Emission Intensity ◽  
Solid Phase ◽  
Temperature Sensing ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Red Emission ◽  
Sensing Properties ◽  
High Emission ◽  
Co Doped ◽  
High Emission Intensity

Through solid-phase reaction technique, Sm3+ and Bi3+ co-doped La3BWO9 phosphors with high emission intensity and sensitive temperature sensing properties have been successfully synthesized. Based on XRD Rietveld refinement, the optimized...

Hydrothermal Synthesis and Characterization of LiZr2(PO4)3

2012 ◽  
Vol 512-515 ◽  
pp. 195-198
Author(s):  
Jin Ye Niu ◽  
Zhi Wei Chen ◽  
Cheng Gong Sun ◽  
Liu Feng ◽  
Zheng Min Li ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Ph Value ◽  
Solid Phase ◽  
Low Cost ◽  
Reaction System ◽  
Xrd Analysis ◽  
Molar Ratio ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Hydrothermal Conditions

Lithium dizirconium phosphate (LiZr2(PO4)3) possesses good ionic conductivity owing to its unique framework structure and can be used as favorable anode material in Li-ion battery. LiZr2(PO4)3 is commonly prepared by solid phase reaction in which higher temperature is needed and pure LiZr2(PO4)3 without other phases is difficult to obtain in the final products. In this paper, low cost hydrothermal synthesis of pure (LiZr2(PO4)3) was studied. Effects of the hydrothermal conditions (molar ratios of Li+ to ZrOCl2, addition of HF, pH values of reaction system and hydrothermal temperatures) on the phase composition of the products were investigated. The results showed that pure LiZr2(PO4)3 was successfully prepared at lower temperature of 80°C for 24h with the addition of HF when the pH value was adjusted to 5.0 and the molar ratio of Li+ to ZrOCl2 was 0.5 with the concentration of ZrOCl2 as 0.6mol/L. The phases and purity of the final products were characterized by XRD analysis.

scholarly journals Preparation and Properties of Co-Doped Magnesium Lanthanum Hexaluminat Blue Ceramics

Ceramics ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Rui Guo ◽  
Qingchun Wang ◽  
Jinxiao Bao ◽  
Xiwen Song
Keyword(s):  
Room Temperature ◽  
Solid Phase ◽  
Color Stability ◽  
Effect Of Temperature ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Doping Amount ◽  
Zirconia Ceramics ◽  
A Value ◽  
Co Doped

The types of blue ceramics are monotonous, mainly alumina and zirconia ceramics, and their colors are not pure, with some green tones (−a* value is not close to 0). In this paper, aluminate blue ceramics (LaMgAl11−xCoxO19) doped with Co were prepared by the high temperature solid-phase reaction method, which enriched the blue ceramics system. The effect of Co content on the color of ceramics was studied, and the optimal doping amount of Co was found. X = 1.0 is the bluest color of the material (−b* = 35.36), and there is almost no noise effect (−a* = −2.71). By studying the effect of temperature on the system, it is found that the color effect is best when the temperature reaches 1450 °C. When the temperature exceeds 1450 °C, it can only promote the synthesis of LaMgAl11O19 phase, and has no effect on the color of ceramics samples. Based on the material’s pure and bright colors, and good color stability at room temperature, it has great potential in the decoration industry, such as the preparation of jewelry or building decoration materials.

scholarly journals Giant Improvement on the Afterglow of Sr4Al14O25:Eu2+,Dy3+ Phosphor by Systematic Investigation on Various Parameters

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Hom Nath Luitel ◽  
Takanori Watari ◽  
Rumi Chand ◽  
Toshio Torikai ◽  
Mitsunori Yada
Keyword(s):  
Solid Phase ◽  
Systematic Investigation ◽  
Rare Earth Ions ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Green Phosphor ◽  
Environment Effect ◽  
Synthesis Parameters ◽  
Reductive Atmosphere ◽  
Initial Intensity

Highly intense, long persistent Sr4Al14O25:Eu2+,Dy3+ blue-green phosphor with different B3+, Eu2+, Dy3+, and Ag+ contents was prepared by solid-phase reaction at various temperatures in reductive atmosphere of 10% H2 in N2. The effects of synthesis parameters like calcination temperature and time, calcination environment, effect of stoichiometry of the host composition, and additives like addition of boron and rare earth ions (Eu, Dy) were studied in detail. Results revealed that the phosphor containing ~40 mol% H3BO3 showed dense and pure Sr4Al14O25 phase with higher emission intensity, but in the samples containing less than 20 mol% H3BO3 mixed phases consisting of Al2O3, SrAl12O19 and SrAl2O4 were observed, while in higher H3BO3 content, SrAl2B2O7 phases predominated. When the stoichiometry of Al/Sr was 3.7, the best phosphorescence and afterglow were noted. The phosphor containing 4 at.% of Eu and 8 at.% of Dy, and 3 at.% Ag exhibited the maximum initial intensity of 5170 mcd·m−2 and the longest persistency of greater than 30 hours over the value of 5 mcd·m−2, higher than the commercial products and applicable for various display applications involving indoor as well as outdoor uses.

Improved Stability of Mn-Doped WO3 Varistor via Doping Cr2O3

2007 ◽  
Vol 336-338 ◽  
pp. 2334-2336
Author(s):  
J.H. Liu ◽  
Y. Zhao ◽  
X.T. Zhu ◽  
Y. Wang
Keyword(s):  
Electrical Properties ◽  
Solid Phase ◽  
Nonlinear Coefficient ◽  
Xrd Analysis ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve ◽  
Improved Stability

In this paper, the effect of Cr2O3 addition on the electrical properties and microstructures of WO3-MnO2 ceramics was studied. The samples were fabricated by the conventional solid phase reaction techniques. The current-voltage curves and impedance spectra of sintered samples were measured at room temperature. The samples without Cr2O3 doping exhibit the max nonlinear coefficient α above 8 in current region from 1mA to 10mA and an unstable characteristic of current-voltage curve for repeat measuring cycle, while the samples doped with Cr2O3 display lower nonlinearity with α about 5 and an improved stability of current-voltage curve at the same conditions. The impedance measurements indicate that the influence on electrical properties comes from grain boundary as well as grain. SEM shows the doping of Cr2O3 into WO3-MnO2 ceramics suppresses obviously the growth of WO3, and XRD analysis reveals the coexistence of WO3 phases with some manganese tungstates and chromium tungstates. The problems related to electrical transporting mechanism were discussed simply.

Sphalerite oxidation by Thiobacillus fertooxidans and Thiobacillus thiooxidans

1995 ◽  
Vol 41 (7) ◽  
pp. 578-584 ◽  
Author(s):  
Oswaldo Garcia Jr. ◽  
Jerry M. Bigham ◽  
Olii H. Tuovinen
Keyword(s):  
Thiobacillus Ferrooxidans ◽  
Solid Phase ◽  
Sulfide Oxidation ◽  
Xrd Analysis ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
Thiobacillus Thiooxidans ◽  
X Ray

Sphalerite (ZnS) oxidation was monitored in Thiobacillus ferrooxidans and Thiobacillus thiooxidans cultures and in abiotic controls by X-ray diffraction (XRD) analysis of solid phases and by chemical analysis of solution composition. X-ray diffraction data revealed no solid-phase reaction products in unsupplemented sphalerite media, whereas minor amounts of S0 accumulated in FeSC4-amended sphalerite media with or without T. ferrooxidans inoculum. Jarosite ((K,Na,H3O,NH4)Fe3(SO4)2(OH)6) also precipitated in the amended T. ferrooxidans cultures. When sphalerite media inoculated with T. thiooxidans were amended with S0, acid production was enhanced, decreasing the pH to 1.1, but Zn dissolution was not accelerated. By comparison with T. thiooxidans, T. ferrooxidans was more efficient in the oxidation of sphalerite.Key words: bioleaching of sphalerite, sphalerite oxidation, Thiobacillus ferrooxidans, Thiobacillus thiooxidans, zinc sulfide oxidation.

scholarly journals Fe3O4@C Nanoparticles Synthesized by In Situ Solid-Phase Method for Removal of Methylene Blue

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Hengli Xiang ◽  
Genkuan Ren ◽  
Yanjun Zhong ◽  
Dehua Xu ◽  
Zhiye Zhang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Solid Phase ◽  
Raw Materials ◽  
Phase Method ◽  
Maximum Adsorption Capacity ◽  
High Catalytic Activity ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
High Concentrations

Fe3O4@C nanoparticles were prepared by an in situ, solid-phase reaction, without any precursor, using FeSO4, FeS2, and PVP K30 as raw materials. The nanoparticles were utilized to decolorize high concentrations methylene blue (MB). The results indicated that the maximum adsorption capacity of the Fe3O4@C nanoparticles was 18.52 mg/g, and that the adsorption process was exothermic. Additionally, by employing H2O2 as the initiator of a Fenton-like reaction, the removal efficiency of 100 mg/L MB reached ~99% with Fe3O4@C nanoparticles, while that of MB was only ~34% using pure Fe3O4 nanoparticles. The mechanism of H2O2 activated on the Fe3O4@C nanoparticles and the possible degradation pathways of MB are discussed. The Fe3O4@C nanoparticles retained high catalytic activity after five usage cycles. This work describes a facile method for producing Fe3O4@C nanoparticles with excellent catalytic reactivity, and therefore, represents a promising approach for the industrial production of Fe3O4@C nanoparticles for the treatment of high concentrations of dyes in wastewater.

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