scholarly journals Luminescence Properties and Energy Transfer of Tm3+-Eu3+ double Doped LiLaSiO4 Phosphors

2021 ◽  
Author(s):  
Xiulan Wu ◽  
Liang Du ◽  
Qiang Ren ◽  
Ou Hai
Keyword(s):  
Energy Transfer ◽  
Electric Dipole ◽  
Solid Phase ◽  
Intensity Variation ◽  
Concentration Quenching ◽  
Luminous Intensity ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Color Control ◽  
Fluorescence Spectrometer

Abstract A series of LiLaSiO4:yTm3+, zEu3+ phosphors were prepared by high temperature solid-phase reaction. The microstructure, luminescence performance and quantum yield of the phosphors are characterized by XRD, SEM and fluorescence spectrometer. When the monitoring wavelength is 360 nm, LiLaSiO4:yTm3+ phosphors showed a sharp emission peak at 460 nm, corresponding to the 7F0→5D2 energy level transition, and the concentration quenching point of Tm3+ ions was y = 0.015. When the monitoring wavelength is 360 nm, LiLaSiO4:yTm3+, zEu3+ phosphors have emission peaks of Tm3+ and Eu3+ ions at 460 and 618 nm, respectively. As the molar mass fraction of Eu3+ ions doped increases, the luminous intensity of Tm3+ ions gradually decrease, and the luminous intensity of Eu3+ ions increases first and then decreases, and the concentration quenching point of Eu3+ ions was z = 0.08. The energy transfer of Tm3+→Eu3+ ions through electric dipole- electric dipole interactions is demonstrated by the luminous intensity variation law and fluorescence lifetime. By changing the doping ratio of Eu3+ and Tb3+ ions, the full-color control of the phosphor luminescent color from blue to red can be achieved.

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.

Microstructure and Mechanical Properties of ZrB2/h-BN Multiphase Ceramics by Low-Temperature Reactive Sintering

2016 ◽  
Vol 697 ◽  
pp. 510-514 ◽  
Author(s):  
Feng Rui Zhai ◽  
Ke Shan ◽  
Ruo Meng Xu ◽  
Min Lu ◽  
Zhong Zhou Yi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Relative Density ◽  
Fracture Strength ◽  
Solid Phase ◽  
Raw Materials ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Microstructure And Mechanical Properties ◽  
Multiphase Ceramics ◽  
Strength And Toughness

In the present paper, the ZrB2/h-BN multiphase ceramics were fabricated by SPS (spark plasma sintering) technology at lower sintering temperature using h-BN, ZrO2, AlN and Si as raw materials and B2O3 as a sintering aid. The phase constitution and microstructure of specimens were analyzed by XRD and SEM. Moreover, the effects of different sintering pressures on the densification, microstructure and mechanical properties of ZrB2/h-BN multiphase ceramics were also systematically investigated. The results show that the ZrB2 was obtained through solid phase reaction at different sintering pressures, and increasing sintering pressure could accelerate the formation of ZrB2 phase. As the sintering pressure increasing, the fracture strength and toughness of the sintered samples had a similar increasing tendency as the relative density. The better comprehensive properties were obtained at given sintering pressure of 50MPa, and the relative density, fracture strength and toughness reached about 93.4%, 321MPa and 3.3MPa·m1/2, respectively. The SEM analysis shows that the h-BN grains were fine and uniform, and the effect of sintering pressure on grain size was inconspicuous. The distribution of grain is random cross array, and the fracture texture was more obvious with the increase of sintering pressure. The fracture mode of sintered samples remained intergranular fracture mechanism as sintering pressure changed, and the grain refinement, grain pullout and crack deflection helped to increase the mechanical properties.

Study of solid-phase reaction between CsNO3 AND V2O5 in the molar ratio 6:5

1980 ◽  
Vol 18 (3) ◽  
pp. 469-476 ◽  
Author(s):  
Ľ. Žúrková ◽  
K. Gáplovská ◽  
V. Suchá
Keyword(s):  
Solid Phase ◽  
Molar Ratio ◽  
Solid Phase Reaction ◽  
Phase Reaction

X-Ray and Magnetic Measurements of TmFeTi2O7

2014 ◽  
Vol 215 ◽  
pp. 470-473 ◽  
Author(s):  
Tamara V. Drokina ◽  
German A. Petrakovskii ◽  
Dmitrii A. Velikanov ◽  
Maksim S. Molokeev
Keyword(s):  
Spin Glass ◽  
Solid Phase ◽  
Magnetic Measurements ◽  
Diffraction Method ◽  
Freezing Temperature ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
History Of

In this paper we are reported about a peculiarity of the crystal structure and the magnetic state of TmFeTi2O7. The compound TmFeTi2O7 has been synthesizedusing the solid-phase reaction method. Using X-ray diffraction method the disorder in the distribution of the iron ions over five nonequivalent crystal sites was observed, also the populations of the iron atoms positions were determined. We show that below Tf = 6 K the magnetization of TmFeTi2O7 depends on the magnetic history of the sample. There are indications for spin glass state. This results allow us to assume the state of spin glass is realized below freezing temperature Tf = 6 K in TmFeTi2O7.

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