Photoluminescence of Lu2O3:Eu3+ Phosphors Obtained by Glycine-nitrate Combustion Synthesis

2005 ◽  
Vol 20 (6) ◽  
pp. 1409-1414 ◽  
Author(s):  
Qiwei Chen ◽  
Ying Shi ◽  
Jiyang Chen ◽  
Jianlin Shi
Keyword(s):  
Grain Size ◽  
Ignition Temperature ◽  
Charge Transfer Band ◽  
Photoluminescence Properties ◽  
Solution Combustion ◽  
Band Position ◽  
Crystallite Sizes ◽  
Glycine Nitrate Combustion ◽  
Peak Emission ◽  
The Eu

Eu3+-doped Lu2O3 phosphors were synthesized through a novel solution combustion route using glycine as the fuel. The influence of the glycine-to-nitrate (G/N) mole ratio on the crystallite size, specific surface area, morphology, and photoluminescence of the synthesized phosphors was investigated. The ignition temperature on the properties of the products was also studied. With G/N ratio increasing from 1.0 to 1.7, the grain size increased from 35 to 118 nm accordingly, resulting in the obvious changes of the photoluminescence properties. Concentration dependence of the emission intensity revealed that the quenching concentration of europium dopant was around 5 mol% for G/N- 1.7. The intensity of the peak emission due to the 5D0 → 7F2 transition of the Eu3+ ions dropped as the grain size decreased. The charge transfer band position of Eu3+-doped lutetia phosphors shifted toward lower energy (red shift) with the reduction of crystallite sizes and also with the increase of Eu3+ concentrations.

VUV-Photoluminescence Properties of (Gd, La)2O2CO3: Eu3+

2014 ◽  
Vol 1052 ◽  
pp. 203-206
Author(s):  
Zhi Long Wang ◽  
Shi Qin Wang ◽  
Nin Yao ◽  
Xing Min Wei
Keyword(s):  
Charge Transfer ◽  
Vacuum Ultraviolet ◽  
Charge Transfer Band ◽  
Broad Band ◽  
Photoluminescence Properties ◽  
Flux Method ◽  
Excitation Spectra ◽  
Red Emission ◽  
Ultraviolet Excitation

(Gd,La)2-x O2CO3:Eux3+(0.01 ≤x≤0.04) were synthesized via a flux method at 400°C, and their photoluminescence properties under vacuum ultraviolet (VUV) excitation were examined. The excitation spectra showed two bands in the region from 125 nm to 300 nm, the first band centered at 190 nm was ascribed to absorption of related CO32- complex, and the second broad band centered at 246nm and 278nm in Gd2O2CO3:Eu3+ was ascribed to the charge transfer band of O2-→ Eu3+. Series samples exhibited red emission at around 611 nm under vacuum ultraviolet excitation corresponding to the 5D0→ 7F2.transition of Eu3+.

scholarly journals Study on the Ignition Process and Characteristics of the Nitrate Ester Plasticized Polyether Propellant

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xiaoting Yan ◽  
Zhixun Xia ◽  
Liya Huang ◽  
Likun Ma ◽  
Xudong Na ◽  
...  
Keyword(s):  
Grain Size ◽  
Energy Density ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Temperature ◽  
Ignition Delay Time ◽  
Ignition Process ◽  
Ignition Energy ◽  
Nitrate Ester ◽  
Nepe Propellant

In this study, a CO2 laser ignition experimental system was built to study the ignition process and characteristics of the Nitrate Ester Plasticized Polyether (NEPE) propellant. The effect of the energy density, ingredients, and the grain size distribution of the propellant on the ignition process was investigated using a CO2 laser igniter, a high-speed camera, and a tungsten-rhenium thermocouple. Four types of NEPE propellants were tested under different laser heat fluxes, and the ignition delay time, the ignition temperature, and the ignition energy were obtained. Experimental results show that the ignition process of the NEPE propellant can be divided into three stages, namely the first-gasification stage, the first-flame stage, and the ignition delay stage. When the energy density is lower than the ignition energy threshold, the ignition process cannot be achieved even under continuous energy loading. The increase of the energy density can lead to the decrease of the ignition delay time but has little effect on the ignition temperature. The ingredients and grain size distribution have great effects on both the ignition delay time and the ignition temperature. The grain size effect of aluminum is the largest compared with that of Ammonium Perchlorate (AP) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), while the grain size effect of AP is larger than that of HMX.

INFLUENCE OF GRAIN SIZE ON MAGNETOCALORIC EFFECT IN THE NANOCRYSTALLINELa0.8Te0.2MnO3

2011 ◽  
Vol 10 (04n05) ◽  
pp. 597-600
Author(s):  
RABINDRA NATH MAHATO ◽  
K. SETHUPATHI ◽  
V. SANKARANARAYANAN
Keyword(s):  
Grain Size ◽  
Landau Theory ◽  
Sol Gel ◽  
Entropy Change ◽  
Ferromagnetic Transition ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Paramagnetic Region ◽  
Rhombohedral Crystal Structure ◽  
Crystallite Sizes

The nanocrystalline La0.8Te0.2MnO3samples are prepared by sol-gel method and show rhombohedral crystal structure with R3c space group at room temperature. The calculated crystallite sizes are ~55 nm, 40 nm and 25 nm for calcined at 700°C, 800°C and 900°C temperatures. The SEM images show the grain size increases as the calcination temperature increases and the values are in good agreement with that obtained from X-ray diffraction analysis. The samples undergo paramagnetic to ferromagnetic transition and follow Curie–Weiss law in the paramagnetic region. The maximum entropy change are ~3.2 J kg-1K-1, 3 J kg-1K-1and 2 J kg-1K-1for a field change of 20 kOe for 55 nm, 40 nm and 25 nm samples respectively. In the framework of Landau theory of phase transition, the experimentally observed magnetic entropy change and theoretical predicted model fits well for all the nanoparticles.

scholarly journals Synthesis, characterization and photoluminescence properties of Gd2O3:Eu3+ nanophosphors prepared by solution combustion method

2010 ◽  
Vol 405 (17) ◽  
pp. 3795-3799 ◽  
Author(s):  
N. Dhananjaya ◽  
H. Nagabhushana ◽  
B.M. Nagabhushana ◽  
R.P.S Chakradhar ◽  
C. Shivakumara ◽  
...  
Keyword(s):  
Combustion Method ◽  
Photoluminescence Properties ◽  
Solution Combustion ◽  
Solution Combustion Method

scholarly journals Synthesis and Photoluminescence Study of Bi3+and Pb2+Activated Ca3(BO3)2

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
A. B. Gawande ◽  
R. P. Sonekar ◽  
S. K. Omanwar
Keyword(s):  
Stokes Shift ◽  
Solution Combustion Synthesis ◽  
Optimum Concentration ◽  
Prepared Phosphor ◽  
Luminescent Materials ◽  
Photoluminescence Properties ◽  
Solution Combustion ◽  
Sem Images ◽  
Synthesized Materials ◽  
Combustion Synthesis Technique

The photoluminescence properties of Pb2+and Bi3+doped Ca3(BO3)2prepared by solution combustion synthesis technique are discussed. The structure of the prepared phosphor is characterized and conformed by XRD and FTIR. SEM images of the prepared materials show irregular grains with agglomerate phenomena. Prepared phosphors achieved the band emissions, respectively, at 365 nm and 335 nm corresponding to the transitionP1→S013. Optimum concentration, critical transfer distance, and Stokes shift of the synthesized materials were measured. These phosphors may provide an efficient kind of luminescent materials for various applications in medical and industry.

Electrospun Europium Complex/Polymer Composite Microfibers and Its Modified Photoluminescence Properties

2011 ◽  
Vol 688 ◽  
pp. 74-79 ◽  
Author(s):  
Hong Xing Yin ◽  
Yun Ze Long ◽  
Fang Yu ◽  
Shuai Jiang Zhao ◽  
Xi Lin She
Keyword(s):  
Optoelectronic Devices ◽  
Europium Complex ◽  
Rare Earth Complex ◽  
Photoluminescence Intensity ◽  
Photoluminescence Properties ◽  
Structural And Optical Properties ◽  
Fluorescence Spectrophotometry ◽  
Complex Polymer ◽  
Scanning Electron ◽  
The Eu

Ribbon-like microfibers of a new composite of europium complex Eu(aspirin)3(Phen) (aspirin is acetylsalicylic acid; Phen represents 1,10-phenanthroline) and polystyrene (PS) were prepared successfully by electrospinning with different mass ratios of Eu(aspirin)3(Phen) complex to PS = 1:10, 1:40 and 1:160. The microfibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and fluorescence spectrophotometry. It was found that the fibers displayed excellent photoluminescence properties compared with rare-earth complex. The photoluminescence intensity and the emission intensity of the peak at 616 nm (5D0→7F2) of Eu-ions increased with the Eu(aspirin)3(Phen) loading. No obvious fluorescence quenching was observed. Further discussion on the structural and optical properties of the microribbons was presented. This kind of materials might be expected to be applied for optical or optoelectronic devices.

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