scholarly journals Optical Investigation of Eu3+ Doped Bi12GeO20 (BGO) Crystals

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 285 ◽  
Author(s):  
M. Kowalczyk ◽  
T.F. Ramazanova ◽  
V.D. Grigoryeva ◽  
V.N. Shlegel ◽  
M. Kaczkan ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Room Temperature ◽  
Transition Probabilities ◽  
Spectroscopic Properties ◽  
Electric Dipole Transition ◽  
Optical Investigation ◽  
Bulk Crystals ◽  
Czochralski Technique ◽  
Uv Excitation ◽  
Transfer Mechanisms

The spectroscopic properties of Eu3+ doped Bi12GeO20 (BGO) sillenite bulk crystals that were grown by the low-thermal-gradient Czochralski technique (LTG Cz) were investigated. The absorption spectra and the emission properties have been measured at room temperature (300 K) and at 10 K. Luminescence was observed both due to the direct Eu3+ ion excitation, as well as under UV excitation due to the energy transfer between Bi3+ and Eu3+ ions. Bi3+ → Eu3+ energy transfer mechanisms in Eu3+:BGO doped host were investigated. The Ωλ parameters, as well as radiative lifetimes, were calculated based upon the Judd-Ofelt formalism. The branching ratios and electric dipole transition probabilities were also determined, based upon the obtained experimental results. Luminescence has been observed from the 5D0,1,2 levels of Eu3+, with emissions from the 5D0 level being the strongest. The strongest observed luminescence band corresponds to the 5D0 → 7F0 transition at 578.7 nm. Reasons for the strong presence of the theoretically forbidden 5D0 → 7F0 emission were investigated.

scholarly journals Er3+ → Ho3+ energy transfer mechanisms at room temperature in YLiF4 single crystals

1987 ◽  
Vol 48 (10) ◽  
pp. 1761-1777 ◽  
Author(s):  
J. Rubin ◽  
A. Brenier ◽  
R. Moncorge ◽  
C. Pedrini
Keyword(s):  
Energy Transfer ◽  
Single Crystals ◽  
Room Temperature ◽  
Transfer Mechanisms

Luminescence, energy-transfer and tunable color properties of single-component Tb3+ and/or Sm3+ doped NaGd(WO4)2 phosphors with UV excitation for use as WLEDs

RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58708-58716 ◽  
Author(s):  
Yan Liu ◽  
Guixia Liu ◽  
Xiangting Dong ◽  
Jinxian Wang ◽  
Wensheng Yu
Keyword(s):  
Energy Transfer ◽  
Single Component ◽  
Color Properties ◽  
Color Tunable ◽  
Uv Excitation ◽  
Transfer Mechanisms

Tb3+ and/or Sm3+ codoped NaGd(WO4)2 microcrystals were prepared and energy transfer mechanisms of WO42− → Sm3+ and Tb3+ → Sm3+ were studied. The color-tunable emissions are investigated, for nUV-LED applications.

Spectroscopic Properties of Cubic SiC on Si

2002 ◽  
Vol 742 ◽  
Author(s):  
Z. C. Feng ◽  
D. N. Talwar ◽  
I. Ferguson
Keyword(s):  
Room Temperature ◽  
Vapour Deposition ◽  
Function Theory ◽  
Chemical Vapour ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Room Temperature Photoluminescence ◽  
Raman Modes ◽  
Indirect Band Gap ◽  
Uv Excitation

ABSTRACTSpectroscopic studies are reported for cubic SiC grown on Si by chemical vapour deposition (CVD) manufacture technique. The UV excitation room temperature photoluminescence (PL)-Raman spectra exhibited 2.3 eV luminescence line due to RT recombination over the SiC indirect band gap. In addition to the optical phonons from cubic SiC we observed new Raman modes near 620 and 833 cm-1. A comprehensive analysis of the dynamical properties of defects using Green's function theory has suggested isolated impurity vibrations to be the possible origin for the additional phonons observed by Raman spectroscopy.

Lattice imaging and pore structure of β ferric oxyhydroxide

1978 ◽  
Vol 36 (1) ◽  
pp. 264-265
Author(s):  
T. Baird ◽  
J.R. Fryer ◽  
S.T. Galbraith
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bulk Material ◽  
Model Structure ◽  
Bulk Crystals ◽  
Lattice Imaging ◽  
Thin Sections ◽  
Ferric Oxyhydroxide ◽  
Resolution Electron ◽  
Hydrolysis Of

Introduction Previously we had suggested (l) that the striations observed in the pod shaped crystals of β FeOOH were an artefact of imaging in the electron microscope. Contrary to this adsorption measurements on bulk material had indicated the presence of some porosity and Gallagher (2) had proposed a model structure - based on the hollandite structure - showing the hollandite rods forming the sides of 30Å pores running the length of the crystal. Low resolution electron microscopy by Watson (3) on sectioned crystals embedded in methylmethacrylate had tended to support the existence of such pores.We have applied modern high resolution techniques to the bulk crystals and thin sections of them without confirming these earlier postulatesExperimental β FeOOH was prepared by room temperature hydrolysis of 0.01M solutions of FeCl3.6H2O, The precipitate was washed, dried in air, and embedded in Scandiplast resin. The sections were out on an LKB III Ultramicrotome to a thickness of about 500Å.

scholarly journals Ultrafast Electron/Energy Transfer and Intersystem Crossing Mechanisms in BODIPY-Porphyrin Compounds

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 312
Author(s):  
Yusuf Tutel ◽  
Gökhan Sevinç ◽  
Betül Küçüköz ◽  
Elif Akhuseyin Yildiz ◽  
Ahmet Karatay ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Visible Region ◽  
Energy Transfer Mechanism ◽  
Free Base ◽  
Pump Probe ◽  
Harvesting Efficiency ◽  
Probe Spectroscopy ◽  
Absorption Features ◽  
Transfer Mechanisms

Meso-substituted borondipyrromethene (BODIPY)-porphyrin compounds that include free base porphyrin with two different numbers of BODIPY groups (BDP-TTP and 3BDP-TTP) were designed and synthesized to analyze intramolecular energy transfer mechanisms of meso-substituted BODIPY-porphyrin dyads and the effect of the different numbers of BODIPY groups connected to free-base porphyrin on the energy transfer mechanism. Absorption spectra of BODIPY-porphyrin conjugates showed wide absorption features in the visible region, and that is highly valuable to increase light-harvesting efficiency. Fluorescence spectra of the studied compounds proved that BODIPY emission intensity decreased upon the photoexcitation of the BODIPY core, due to the energy transfer from BODIPY unit to porphyrin. In addition, ultrafast pump-probe spectroscopy measurements indicated that the energy transfer of the 3BDP-TTP compound (about 3 ps) is faster than the BDP-TTP compound (about 22 ps). Since the BODIPY core directly binds to the porphyrin unit, rapid energy transfer was seen for both compounds. Thus, the energy transfer rate increased with an increasing number of BODIPY moiety connected to free-base porphyrin.

scholarly journals Energy transfer mechanisms and resolvent analysis in the cylinder wake

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Bo Jin ◽  
Sean Symon ◽  
Simon J. Illingworth
Keyword(s):  
Energy Transfer ◽  
Cylinder Wake ◽  
Transfer Mechanisms

scholarly journals Temperature-Dependent Stimulated Emission Cross-Section in Nd3+:YLF Crystal

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 431
Author(s):  
Giorgio Turri ◽  
Scott Webster ◽  
Michael Bass ◽  
Alessandra Toncelli
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Room Temperature ◽  
Radiative Decay ◽  
Emission Cross Section ◽  
Spectroscopic Properties ◽  
Stimulated Emission ◽  
Different Temperatures ◽  
Stimulated Emission Cross Section ◽  
Semi Empirical

Spectroscopic properties of neodymium-doped yttrium lithium fluoride were measured at different temperatures from 35 K to 350 K in specimens with 1 at% Nd3+ concentration. The absorption spectrum was measured at room temperature from 400 to 900 nm. The decay dynamics of the 4F3/2 multiplet was investigated by measuring the fluorescence lifetime as a function of the sample temperature, and the radiative decay time was derived by extrapolation to 0 K. The stimulated-emission cross-sections of the transitions from the 4F3/2 to the 4I9/2, 4I11/2, and 4I13/2 levels were obtained from the fluorescence spectrum measured at different temperatures, using the Aull–Jenssen technique. The results show consistency with most results previously published at room temperature, extending them over a broader range of temperatures. A semi-empirical formula for the magnitude of the stimulated-emission cross-section as a function of temperature in the 250 K to 350 K temperature range, is presented for the most intense transitions to the 4I11/2 and 4I13/2 levels.

Room temperature phosphorimetric determination of bromate in flour based on energy transfer

Talanta ◽  
2013 ◽  
Vol 116 ◽  
pp. 231-236 ◽  
Author(s):  
Mario Menendez-Miranda ◽  
Maria T. Fernandez-Argüelles ◽  
Jose M. Costa-Fernandez ◽  
Rosario Pereiro ◽  
Alfredo Sanz-Medel
Keyword(s):  
Energy Transfer ◽  
Room Temperature

The afterglow and energy transfer mechanisms of active nitrogen

1970 ◽  
Vol 33 (1) ◽  
pp. 269-306 ◽  
Author(s):  
J Anketell ◽  
R W Nicholls
Keyword(s):  
Energy Transfer ◽  
Active Nitrogen ◽  
Transfer Mechanisms
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