Luminescent Properties of As-Grown and Vacuum Annealed LiNbO3 Single Crystals

2013 ◽  
Vol 200 ◽  
pp. 199-202
Author(s):  
Dmytro Yu. Sugak ◽  
Andriy P. Luchechko
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Annealed Sample ◽  
Luminescence Spectra ◽  
Excitation Spectra ◽  
X Ray ◽  
Grown Sample ◽  
Different Types

This paper reports on the luminescent properties of the congruent as-grown and vacuum annealed LiNbO3 single crystals at the UV and X-ray excitations. The shape of excitation spectra is similar for all emission bands in as-grown sample as well as in vacuum annealed sample. The emission spectra (exc=235 nm) observed in the spectral region 250…800 nm at room temperature consist of five elementary bands. Correlation of the relative intensities bands in luminescence spectra under different types of excitation and their temperature dependencies were determined. The most intensitive maxima in as-grown sample are observed at 295 and 691 nm. The main maximum after vacuum annealing is peaked around 295 nm.

scholarly journals Synthesis and Luminescent Properties of Eu3+/Tb3+ Rare Earth Ions Doped Li2SrSiO4 Phosphors

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Kaitao Yu ◽  
Lifang Wei ◽  
Jiaqi Shen
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Band ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Rare Earth Ions ◽  
Luminescent Materials ◽  
Excitation Spectra ◽  
Solid State Method ◽  
X Ray ◽  
Uv Visible

The series of luminescent materials of Eu3 +, Tb3 + doped Li2SrSiO4 were synthesized by a high-temperature solid-state method. The phase purity of the samples was measured by X-ray powder diffraction (XRD). The luminescent properties of the samples were studied by UV-visible excitation spectra and emission spectra The It is found that the strong absorption of Eu3 + doped Li2-xSr1-xEuxSiO4 is from the 250 ~ 290 nm charge transfer band of Eu3 + and the 7F0 → 5L6 absorption transition of 393 nm. The strongest emission of the emission spectra at 393 nm is 614 nm and 701 nm, respectively, from the 5D0 → 7F2 and 5D0 → 7F4 transitions of Eu3 +. Tb3 + doped sample Li2-xSr1-xTb xSiO4 excitation spectrum is mainly composed of Tb3 + ion fd transition and charge transfer band composed of broadband, the strongest absorption at 269 nm, the emission of the main emission of 5D4 → 7F5 transition (542 nm).

Luminescence of LiF Crystals Doped with Metal Oxide Impurities

2016 ◽  
Vol 685 ◽  
pp. 623-626 ◽  
Author(s):  
Vladimir I. Korepanov ◽  
Pavel V. Petikar ◽  
Guang Hui Ge
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Spectral Range ◽  
Luminescent Properties ◽  
Electron Bombardment ◽  
Luminescence Spectra ◽  
Excitation Spectra ◽  
Pulsed Cathodoluminescence ◽  
Different Types ◽  
Oxygen Complexes

The luminescence spectra and luminescence excitation spectra have been investigated in the spectral range of 6.5–4.4 eV. Pulsed cathodoluminescence of LiF-WО3 and LiF-TiО2 crystals has been studied in the temperature range of 20–300 K. All LiF crystals doped with metal oxides are found to have similar luminescent properties and identical structure of the luminescence centers. It is assumed that photon and electron bombardment induces excitation of different types of О2− oxygen centers perturbed by impurities and Fe2О3, WО3 and TiО2 included in the oxygen complexes.

Self-Assembled NaTb1−x Eux(MoO4)2: Synthesis and Luminescence Properties

2016 ◽  
Vol 16 (4) ◽  
pp. 3700-3704
Author(s):  
Xiaoqing Liu ◽  
Lingnan Qu ◽  
Shuo Wang ◽  
Lv Li ◽  
Yiguo Su ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Luminescent Properties ◽  
Excitation Wavelength ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Enhanced Luminescence ◽  
Self Assembled

Novel 3D Eu3+ doped NaTb(MoO4)2 composites were successfully self-assembled by a facile hydrothermal treatment. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectra were used to characterize the structures, morphologies and the luminescent properties of as-prepared products. Emission and excitation spectra showed that the phosphor exhibits a dominant red emission at 615 nm with excitation wavelength of 465 nm at room temperature. The emission intensity increased with the increase of Eu3+ concentrations for the investigated range of 2–10 mol% Eu3+ doping in NaTb(MoO4)2. The doping of Eu3+ results in a distorted Eu–O8 cluster and enhanced luminescence intensity.

Preparation and Luminescent Properties of Sm3+ Doped Ca3SiO4Cl2 Phosphor

2013 ◽  
Vol 788 ◽  
pp. 48-51 ◽  
Author(s):  
Shao Hua Tian ◽  
Xu Li ◽  
Bao Zhu Yang ◽  
Li Guan ◽  
Fei Su ◽  
...  
Keyword(s):  
Room Temperature ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Concentration Quenching ◽  
White Led ◽  
Quenching Mechanism ◽  
Ion Content ◽  
Red Phosphor ◽  
X Ray ◽  
Host Structure

A new red phosphor Ca3SiO4Cl2:Sm3+ has been synthesized and its luminescent properties have been investigated. The X-ray powder diffraction (XRD) was measured for studying the host structure. The excitation and emission spectra were measured at room temperature. The effect of Sm3+ ion content on the luminescent intensity and concentration quenching mechanism were studied. The results suggest that this phosphor maybe a good candidate of red phosphor for near UV-based white LED.

Effect of trytophan as dopant on potassium acid phthalate single crystals

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Evaporation Technique ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

ELECTRON STRUCTURE INVESTIGATIONS OF InGaP/GaAs(100) HETEROSTRUCTURES WITH InP QUANTUM DOTS

2007 ◽  
Vol 06 (03n04) ◽  
pp. 215-219
Author(s):  
E. P. DOMASHEVSKAYA ◽  
V. A. TEREKHOV ◽  
V. M. KASHKAROV ◽  
S. YU. TURISHCHEV ◽  
S. L. MOLODTSOV ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Emission Spectra ◽  
Luminescence Spectra ◽  
Partial Density ◽  
Edge Structure ◽  
X Ray ◽  
Metal Organic ◽  
Structure Investigations ◽  
First Time ◽  
Inp Quantum Dots

Ultrasoft X-ray emission spectra (USXES) and X-ray absorption near-edge structure (XANES) spectra with the use of synchrotron radiation in the range of P L2,3-edges were obtained for the first time for nanostructures with InP quantum dots grown on GaAs 〈100〉 substrates by vapor-phase epitaxy from metal–organic compounds. These spectra represent local partial density of states in the valence and conduction bands. The additional XANES peak is detected; its intensity depends on the number of monolayers forming quantum dots. Assumptions are made on the band-to-band origin of luminescence spectra in the studied nanostructures.

Generation of Defects and Strain by Ion Implantation in Ge (100) Single Crystals, and in Pseudomorphic GexSi1-x Films Grown on Si (100)

1992 ◽  
Vol 262 ◽  
Author(s):  
D. Y. C. Lie ◽  
A. Vantomme ◽  
F. Eisen ◽  
M. -A. Nicolet ◽  
V. Arbet-Engels ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Room Temperature ◽  
Defect Concentration ◽  
Double Crystal ◽  
X Ray ◽  
Positive Strain ◽  
Independent Coefficient ◽  
The Relationship ◽  
Si Ion Implantation

ABSTRACTWe have studied the damage and strain produced in Ge (100) single crystals by implantation of various doses of 300 keV 28Si ions at room temperature. The analyzing tools were x-ray double-crystal diffractometry, and MeV 4He channeling spectrometry. The damage induced by implantation produces positive strain in Ge (100). The maximum perpendicular strain and maximum defect concentration rise nonlinearly with increasing dose. These quantities are linearly related with a dose-independent coefficient of ∼ 0.013 for Ge (100) single crystals implanted at room temperature. The results are compared with those available for Si (100) self-implantation. We have also monitored the strain and defects generated in pseudomorphic Ge0.1Si0.9/Si (100) films induced by room temperature 28Si ion implantation. It is found that the relationship between the strain and defect concentration induced by ion implantation is no longer a simple linear one.

Synthesis of CaWO4:(Eu3+,Tb3+) Thin Films by a Two-Step Method at Room Temperature

2013 ◽  
Vol 710 ◽  
pp. 170-173
Author(s):  
Lian Ping Chen ◽  
Yuan Hong Gao
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Composition ◽  
Room Temperature ◽  
Electrochemical Techniques ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Rare Earth Doped

It is hardly possible to obtain rare earth doped CaWO4thin films directly through electrochemical techniques. A two-step method has been proposed to synthesize CaWO4:(Eu3+,Tb3+) thin films at room temperature. X-ray diffraction, energy dispersive X-ray analysis, spectrophotometer were used to characterize their phase, composition and luminescent properties. Results reveal that (Eu3+,Tb3+)-doped CaWO4films have a tetragonal phase. When the ratio of n (Eu)/n (Tb) in the solution is up to 3:1, CaWO4:(Eu3+,Tb3+) thin film will be enriched with Tb element; on the contrary, when the ratio in the solution is lower than 1:4, CaWO4:(Eu3+,Tb3+) thin film will be enriched with Eu element. Under the excitation of 242 nm, sharp emission peaks at 612, 543, 489 and 589 nm have been observed for CaWO4:(Eu3+,Tb3+) thin films.

Synthesis and Characterization of Y2O3:Eu3+ Film Derived by Sol-Gel Processing

2007 ◽  
Vol 336-338 ◽  
pp. 593-596
Author(s):  
Chun Yang ◽  
Jun Ying Zhang ◽  
Hai Bing Feng ◽  
Wei Chang Hao ◽  
Tian Min Wang
Keyword(s):  
Raw Materials ◽  
Sol Gel ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Dip Coating ◽  
Organic Additive ◽  
Excitation Spectra ◽  
Excitation Peak ◽  
Close Relationship ◽  
Dip Coating Technique

Y2O3:Eu3+ thin film was synthesized by sol-gel method with inorganic salt raw materials, and the crystal structure and luminescent properties were investigated. By adding organic additive to the sol, a homogeneous film with high luminescent intensity could be obtained by dip-coating technique on the surface of alumina sheet and quartz glass. Structures of the films were studied by XRD and SEM. The excitation spectra of the films showed a wide excitation peak from 200nm to 260nm, and the emission spectra had a strongest emission peak at 611nm which revealed a close relationship with the calcining temperature.

Crystallinity of YBa2Cu3O7−x single crystals grown by the pulling method

1996 ◽  
Vol 11 (4) ◽  
pp. 804-812 ◽  
Author(s):  
Y. Namikawa ◽  
M. Egami ◽  
S. Koyama ◽  
Y. Shiohara ◽  
H. Kutami
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Growth Direction ◽  
Annealed Sample ◽  
Seed Crystal ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Crystal Seed ◽  
Better Than

Large YBa2Cu3O7−x (Y123) single crystals (larger than 13 mm cubed) have been grown along the c-axis reproducibly by the modified pulling method. The crystallinity of Y123 single crystal was investigated by x-ray diffraction and x-ray topography. Crystals grown from an MgO single crystal seed had some low angle subgrain boundaries which tilted 0.1–0.8° from each other. These grain boundaries originated from the seed crystal, and the subgrains were extended along the growth direction from the seed crystal. Y123 single crystals with no marked subgrains in the whole area were obtained by using Y123 single subgrain crystal seeds. FWHM of the x-ray rocking curve for the crystal so produced was about 0.14°, which was much better than the spectrum consisting of several separated peaks obtained from the previous crystals. Tc onset of the annealed sample was about 93.6 K, and the transition width was about 0.9 K. The low angle subgrain boundaries did not seem to be effective pinning centers for the magnetic flux.

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