scholarly journals Neutron Rietveld Analysis for Optimized CaMgSi2O6:Eu2+ and its Luminescent Properties

2005 ◽  
Vol 20 (8) ◽  
pp. 2061-2066 ◽  
Author(s):  
Won Bin Im ◽  
Yong-Il Kim ◽  
Jong Hyuk Kang ◽  
Duk Young Jeon ◽  
Ha Kyun Jung ◽  
...  
Keyword(s):  
Rietveld Refinement ◽  
Goodness Of Fit ◽  
Luminescent Properties ◽  
Energy Transfer Mechanism ◽  
Activator Concentration ◽  
Conventional Solid State Reaction ◽  
Multipolar Interaction ◽  
Synthesis Conditions ◽  
Transfer Distance ◽  
Critical Transfer Distance

We optimized synthesis conditions of blue-emitting CaMgSi2O6:Eu2+ (CMS:Eu2+) with conventional solid-state reaction and successfully determined structure parameters by Rietveld refinement method with neutron powder diffraction data. The final weighted R-factor Rwp was 6.42% and the goodness-of-fit indicator S (= Rwp/Re) was 1.34. The refined lattice parameters of CMS:Eu2+ were a = 9.7472(3) Å, b = 8.9394(2) Å, and c = 5.2484(1) Å. The β angle was 105.87(1)°. The concentration quenching process was observed, and the critical quenching concentration of Eu2+ in CMS:Eu2+ was about 0.01 mol and critical transfer distance was calculated as 12 Å. With the help of the Rietveld refinement and Dexter theory, the critical transfer distance was also calculated as 27 Å. In addition, the dominant multipolar interaction of CMS:Eu2+ was investigated from the relationship between the emission intensity per activator concentration and activator concentration. The dipole–dipole interaction was a dominant energy transfer mechanism of electric multipolar character of CMS:Eu2+.

scholarly journals CaSnO 3: Yb 3+, Er 3+, Ho 3+ system synthesis and study of its luminescence under IR excitation

2018 ◽  
Vol 4 (2) ◽  
pp. 71-75
Author(s):  
Ul’ana A. Mar’ina ◽  
Viktor A. Vorob’ev ◽  
Alexandr P. Mar’in
Keyword(s):  
Laser Excitation ◽  
Earth Metal ◽  
Luminescent Properties ◽  
Ion Concentration ◽  
Semiconductor Diode ◽  
Luminescence Spectra ◽  
Energy Transfer Mechanism ◽  
Absorbed Energy ◽  
Ir Radiation ◽  
Synthesis Conditions

Solid state synthesis of Perovskite-like calcium stannate structure activated with three rare-Earth metal ions Yb3+,Er3+,Но3+ has been studied. The formation of the CaSnO3 : Yb3+,Er3+,Но3+ luminescent structure requires the following synthesis conditions: anneal temperature 1250 °C and duration at least 18 h. The luminescent properties of the specimens have been studied under 960 nm semiconductor diode laser excitation. The luminescence spectra contain bands in the visible and IR spectral regions. Yb3+ ions have been shown to act predominantly as sensibilizers capable of transferring part of absorbed energy to Er3+ and Но3+ ions thus intensifying their respective luminescence peaks. Er3+ ions also transfer part of absorbed energy to Но3+ ions leading to an increase in the intensity of the 1194 and 1950 nm IR luminescence bands. A schematic of possible energy transitions in the CaSnO3 : Yb3+,Er3+,Но3+ system under 960 nm laser excitation has been suggested. The energy transfer mechanism between Yb3+,Er3+ and Но3+ions has been described in detail. The luminescence intensity of the luminophore has been studied at 994, 1194, 1550 and 1950 nm as a function of Но3+ion concentration. The peak intensity of the 1194 and 1950 nm bands is the highest at a Но3+ion concentration of 0.007 at.fr. It has been suggested to use the CaSnO3 : Yb3+,Er3+,Но3+ luminescent structure for radiation sources capable of converting 960 nm IR radiation to ~2000 nm IR radiation.

Luminescent Properties of LiTaO3:Tm3+, Yb3+ Phosphors Prepared by Ball Milling Method

2013 ◽  
Vol 423-426 ◽  
pp. 426-429
Author(s):  
Xin Ze Wang ◽  
Zhong Xin Liu ◽  
Hong Jian Gao ◽  
Yani Jing ◽  
Chang Lin Li ◽  
...  
Keyword(s):  
Solid State ◽  
Ball Milling ◽  
Solid State Reaction ◽  
Blue Emission ◽  
Photoluminescence Property ◽  
Luminescent Properties ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Conventional Solid State Reaction ◽  
Energy Ball

LiTaO3: Tm3+, Yb3+powders were synthesized by a high-energy ball-milling (HEB) method compared with the conventional solid-state reaction (SSR) method. Under the excitation of 980 nm laser, the strong blue emission (477 nm) band is observed and attributed to1G4-3H6of Tm3+. Because of it causing high local temperature and narrow particles size, increasing the contact area between the particles and improved crystallinity of the host, synthesis by high-energy ball milling show higher photoluminescence (PL) intensity compared to the solid state reaction method. In the process of mechanical milling, Tm3+, Yb3+co-doped LiTaO3phosphors with high photoluminescence property could be achieved at a relatively low reaction temperature.

A new luminescent host material K3GdB6O12: synthesis, crystal structure and luminescent properties activated by Sm3+

2018 ◽  
Vol 233 (6) ◽  
pp. 411-419 ◽  
Author(s):  
Dan Zhao ◽  
Cong-Kui Nie ◽  
Ye Tian ◽  
Bao-Zhong Liu ◽  
Yun-Chang Fan ◽  
...  
Keyword(s):  
Solid State ◽  
Uv Light ◽  
Three Dimensional ◽  
Visual Display ◽  
Luminescent Properties ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Promising Candidate ◽  
Conventional Solid State Reaction ◽  
Host Matrix

Abstract A new borate compound K3GdB6O12 has been prepared using a high temperature flux method and structurally characterized by single crystal X-ray diffraction analysis. The structure can be described as a three-dimensional framework that is composed of [B5O10]5− groups, K+ ions and Gd3+ ions. In this structure, one crystallographic distinct site is mixed occupied by K and Gd atoms at the molar ratio of 1:1. Furthermore, Sm3+ ion was used as the activator to test primary of K3GdB6O12 to be used as a luminescent host matrix. A series of phosphors K3Gd1−xB6O12:xSm3+ were synthesized by conventional solid-state reaction. The photoluminescence properties and concentration quenching of the prepared phosphors were investigated. The results show that K3Gd1−xB6O12:xSm3+ can be efficiently excited by near-UV light. K3Gd1−xB6O12:xSm3+ might be a promising candidate for visual display and solid-state lighting as an orange emission phosphor.

Luminescent properties of Y2O3:Eu3+ nanophosphor prepared from urea added precursor using flame spray pyrolysis

2009 ◽  
Vol 24 (8) ◽  
pp. 2584-2588 ◽  
Author(s):  
Jae Seok Lee ◽  
Se Jin Kim ◽  
Tae Kon Kim ◽  
Rajiv K. Singh ◽  
Madhav B. Ranade
Keyword(s):  
Electron Microscopy ◽  
Spray Pyrolysis ◽  
Red Light ◽  
Luminescent Properties ◽  
Flame Spray Pyrolysis ◽  
Cubic Phase ◽  
Flame Spray ◽  
X Ray Diffraction ◽  
Synthesis Conditions ◽  
Transmission Electron

Y2O3:Eu3+ nanophosphor was synthesized by flame spray pyrolysis (FSP) from urea added nitrate based liquid precursor. In this study, urea serves as fuel and subsequently provides additional heat in the flame zone during the synthesis of phosphor particles. The end product shows cubic phase Y2O3:Eu3+ nanophosphor successfully prepared by FSP without heat treatment. The influence of synthesis conditions such as different mol of urea and nitrate source materials in aqueous solution, and doping concentration on luminescent properties, were investigated. The characteristics of nanophosphor such as crystallinity and morphology under various experiments of conditions were carried out by x-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM). The particle size of product was found to be in the range of 20–30 nm from transmission electron microscopy (TEM). In photoluminescence (PL) properties, Y2O3:Eu3+ nanophosphor emitted red light with a peak wavelength of 609 nm when excited with 398 nm wavelength photons.

scholarly journals Luminescent Properties and Energy Transfer Mechanism of Gd3+ and Eu2+ Co-doped Phosphate Glasses

2015 ◽  
Vol 28 (4) ◽  
pp. 487-491 ◽  
Author(s):  
Qian Wang ◽  
Shao-Ye Ouyang ◽  
Wei-Huan Zhang ◽  
Bin Yang ◽  
Yue-Pin Zhang ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Luminescent Properties ◽  
Phosphate Glasses ◽  
Transfer Mechanism ◽  
Energy Transfer Mechanism ◽  
Co Doped

scholarly journals Synthesis and luminescent properties of novel red-emitting M7Sn(PO4)6:Eu3+(M= Sr,Ba) phosphors

2018 ◽  
Vol 12 (1) ◽  
pp. 8-12
Author(s):  
Guo Feng ◽  
Weihui Jiang ◽  
Jianmin Liu ◽  
Cong Li ◽  
Quan Zhang
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Red Light ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
Formula Unit ◽  
Conventional Solid State Reaction ◽  
Light Emitting ◽  
Reaction Method ◽  
Uv Leds

Novel Eu3+-activated M7Sn(PO4)6 (where M = Sr, Ba) red-emitting phosphors were synthesized via conventional solid-state reaction method at 1200 ?C for 2 h. The luminescence properties of the prepared samples and quenching concentration of Sr7-xSn(PO4)6 :xEu3+ and Ba7-xSn(PO4)6 :xEu3+ were investigated. These phosphors can be efficiently excited by UV (395 nm) and visible blue (465 nm) light nicely matching the output wavelengths of the near-UV LEDs and InGaN blue LED chips and emit the red light. The critical concentrations of the Eu3+ activator were found to be 0.175mol and 0.21mol per formula unit for Sr7-xSn(PO4)6 :xEu3+ and Ba7-xSn(PO4)6 :xEu3+, respectively. The M7-xSn(PO4)6 :xEu3+ (M = Sr, Ba) phosphor may be a good candidate for light-emitting diodes application.

scholarly journals Luminescent properties of a novel reddish-orange phosphor Eu-activated KLaSiO4

2019 ◽  
Vol 37 (2) ◽  
pp. 296-300
Author(s):  
Guo Feng ◽  
Wei-Hui Jiang ◽  
Jian-Min Liu
Keyword(s):  
Critical Concentration ◽  
Luminescent Properties ◽  
Conventional Solid State Reaction ◽  
Excellent Thermal Stability ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
White Light Emitting Diodes ◽  
Potential Use ◽  
Orange Luminescence ◽  
Reddish Orange

AbstractA novel reddish-orange emitting phosphor Eu-activated KLaSiO4 was synthesized by the conventional solid-state reaction at 1200 °C. The luminescence properties of KLaSiO4:Eu phosphor were investigated, and the critical concentration of the activator ion (Eu3+) was established as 0.02 mol per formula unit. Chromaticity coordinates of a typical KLa0.98SiO4:0.02Eu phosphor were x = 0.614 and y = 0.385. The phosphor exhibited reddish-orange luminescence with dominating emission at 612 nm, corresponding to 5D0 → 7F2 of Eu3+. Furthermore, the phosphor was characterized by excellent thermal stability, implying its potential use in white light emitting diodes.

Luminescent properties and energy transfer mechanism from Tb3+ to Eu3+ doped in Y3Al5O12 phosphors

2020 ◽  
Vol 822 ◽  
pp. 153651 ◽  
Author(s):  
Wellisson S. Silveira ◽  
Patresio A.M. Nascimento ◽  
Ariosvaldo J.S. Silva ◽  
Marcos V.dos S. Rezende
Keyword(s):  
Energy Transfer ◽  
Luminescent Properties ◽  
Transfer Mechanism ◽  
Energy Transfer Mechanism
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