scholarly journals Nano-Crystallization of Ln-Fluoride Crystals in Glass-Ceramics via Inducing of Yb3+ for Efficient Near-Infrared Upconversion Luminescence of Tm3+

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1033
Author(s):  
Jianfeng Li ◽  
Yi Long ◽  
Qichao Zhao ◽  
Shupei Zheng ◽  
Zaijin Fang ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Near Infrared ◽  
Upconversion Luminescence ◽  
Glass Ceramics ◽  
Upconversion Emission ◽  
Ceramic Composites ◽  
Wide Range ◽  
Transmission Window ◽  
Optical Applications ◽  
Upconversion Emissions

Transparent glass-ceramic composites embedded with Ln-fluoride nanocrystals are prepared in this work to enhance the upconversion luminescence of Tm3+. The crystalline phases, microstructures, and photoluminescence properties of samples are carefully investigated. KYb3F10 nanocrystals are proved to controllably precipitate in the glass-ceramics via the inducing of Yb3+ when the doping concentration varies from 0.5 to 1.5 mol%. Pure near-infrared upconversion emissions are observed and the emission intensities are enhanced in the glass-ceramics as compared to in the precursor glass due to the incorporation of Tm3+ into the KYb3F10 crystal structures via substitutions for Yb3+. Furthermore, KYb2F7 crystals are also nano-crystallized in the glass-ceramics when the Yb3+ concentration exceeds 2.0 mol%. The upconversion emission intensity of Tm3+ is further enhanced by seven times as Tm3+ enters the lattice sites of pure KYb2F7 nanocrystals. The designed glass ceramics provide efficient gain materials for optical applications in the biological transmission window. Moreover, the controllable nano-crystallization strategy induced by Yb3+ opens a new way for engineering a wide range of functional nanomaterials with effective incorporation of Ln3+ ions into fluoride crystal structures.

Phase-Selective Hydrothermal Preparation and Upconversion Luminescence of NaYF4:Yb3+,Tm3+

2016 ◽  
Vol 690 ◽  
pp. 120-125 ◽  
Author(s):  
Thanataon Pornpatdetaudom ◽  
Karn Serivalsatit
Keyword(s):  
Reaction Time ◽  
Near Infrared ◽  
Hexagonal Phase ◽  
Upconversion Luminescence ◽  
Upconversion Emission ◽  
High Energy ◽  
Lanthanide Ions ◽  
Cubic Phase ◽  
Good Efficiency ◽  
Hydrothermal Temperature

Upconversion luminescence materials have been proved to have a good efficiency on converting low energy light to high energy light. These materials have received considerable attentions for many applications such as bio-labels, sensors, using for developing solar cells and photocatalytic applications under sunlight. Among many inorganic host materials, NaYF4 has been proved to be the best for doping lanthanide ions and have a good upconversion emission due to its low phonon energy, chemical stability, and transparency in the near infrared to ultraviolet range. In this study, NaYF4:Yb3+,Tm3+ upconversion luminescence materials were synthesized by hydrothermal method at temperature of 90 to 200 °C for period between 1 to 24 hours. The synthesized NaYF4:Yb3+,Tm3+ were characterized by X-ray diffraction, scanning electron microscopy, and fluorescence spectroscopy. The hydrothermal temperature and reaction time have strongly influence on phases and upconversion emission of the synthesized NaYF4:Yb3+,Tm3+. At 90 °C for 1 hour of reaction time, the pure cubic phase of NaYF4:Yb3+,Tm3+ was found. After increasing temperature and reaction time, the NaYF4:Yb3+,Tm3+ converted from cubic phase to hexagonal phase. Under excitation of 980 nm diode laser, the hexagonal NaYF4:Yb3+,Tm3+ exhibited the emission wavelength at about 656 nm (3F2 → 3H6), 469, 492, 552 nm (1G4 → 3H6), 537 nm (1D2 → 3H5), 450, 461 nm (1D2 → 3F4), 362 nm (1D2 → 3H6) and 345 nm (1I6 → 3F4). The upconversion emission intensity of the hexagonal NaYF4:Yb3+,Tm3+ was much stronger, compared with that of the cubic NaYF4:Yb3+,Tm3+.

Crystallization and Optical Properties of Sr3Al2O6-SrAl2O4 Eutectic Glass

2018 ◽  
Vol 281 ◽  
pp. 163-168
Author(s):  
Jia Xi Liu ◽  
Nan Lu ◽  
Gang He ◽  
Xiao Yu Li ◽  
Jian Qiang Li ◽  
...  
Keyword(s):  
Near Infrared ◽  
Glass Ceramics ◽  
Photo Luminescence ◽  
Phase Evolution ◽  
Optical Transmittance ◽  
Infrared Region ◽  
Treatment Temperature ◽  
Glass Beads ◽  
Heat Treated ◽  
Wide Range

SrO-Al2O3 ceramics has prospective applications due to its photo-luminescence and persistent afterglow properties. Sr3Al2O6-SrAl2O4 eutectic glass was prepared by using the aerodynamic levitator equipped with a CO2 laser device. The prepared Sr3Al2O6-SrAl2O4 eutectic glass beads were further heat-treated at temperature from 880°C to 980°C. The phase evolution, crystallization behavior, optical transmittance and mechanical properties of the annealed eutectic glass ceramics were investigated. The as-prepared glass is colorless and transparent over a wide range from ultraviolet to near-infrared region, and the average in-line transmittance is over 80% in the range of 260-3200nm. There were two crystal phases Sr3Al2O6 and SrAl2O4 crystallized from the glass beads. With increasing heat-treatment temperature, the transparency of the samples decreased, and the hardness increased. The prepared Sr3Al2O6-SrAl2O4 eutectic glass and glass ceramics may be a promising candidate for the development of photo-luminescence and persistent afterglow materials.

UPCONVERSION LUMINESCENCE ENHANCEMENT OF NaYF4:Yb3+, Er3+ NANOPARTICLES ON INVERSE OPAL SURFACE

2014 ◽  
Vol 21 (01) ◽  
pp. 1450017 ◽  
Author(s):  
JIAYAN LIAO ◽  
ZHENGWEN YANG ◽  
HANGJUN WU ◽  
SHENFENG LAI ◽  
JIANBEI QIU ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Upconversion Emission ◽  
Band Gaps ◽  
Inverse Opal ◽  
Photonic Band Gaps ◽  
Selective Reflection ◽  
Inverse Opals ◽  
Upconversion Emissions ◽  
Photonic Band ◽  
Co Doped

LaPO 4 inverse opal photonic crystals with different photonic band gaps were fabricated by template-assisted method. The Yb 3+/ Er 3+ co-doped NaYF 4 nanoparticles were deposited on the surfaces of the inverse opals, and their up-conversion emission properties were investigated. The upconversion emissions of Yb 3+/ Er 3+ co-doped NaYF 4 nanoparticles on the inverse opal surfaces have been enhanced when the upconversion emission bands of the nanoparticles are in the range of photonic band gaps of the inverse opals, which is attributed to an efficient and selective reflection of photonic band gaps.

scholarly journals Hydrothermal Synthesis and Tunable Multicolor Upconversion Emission of Cubic Phase Y2O3Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Haibo Wang ◽  
Chao Qian ◽  
Zhigao Yi ◽  
Ling Rao ◽  
Hongrong Liu ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Upconversion Emission ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Light Yellow ◽  
Color Displays ◽  
Transmission Electron ◽  
Subsequent Calcination ◽  
Upconversion Emissions

Highly crystalline body-centered cubic structure Y2O3with lanthanide (Ln) codopants (Ln = Yb3+/Er3+and Yb3+/Ho3+) has been synthesized via a moderate hydrothermal method in combination with a subsequent calcination. The structure and morphology of Y(OH)3precursors and Y2O3nanoparticles were characterized by X-ray diffraction and transmission electron microscopy. The results reveal that the Y2O3nanoparticles possess cubic phase and form the quasispherical structure. The upconversion luminescence properties of Y2O3nanoparticles doped with different Ln3+(Yb3+/ Er3+and Yb3+/ Ho3+) ions were well investigated under the 980 nm excitation. The results show that the Yb3+/Er3+and Yb3+/Ho3+codoped Y2O3nanoparticles exhibit strong red and light yellow upconversion emissions, respectively. It is expected that these Y2O3nanoparticles with tunable multicolor output and intense red upconversion emission may have potential application in color displays and biolabels.

Upconversion Emission of Infrared Excited Er3+-Doped Transparent Glass Ceramics Containing CaF2 Nano-Crystals

2007 ◽  
Vol 336-338 ◽  
pp. 1846-1848
Author(s):  
Da Qin Chen ◽  
Yuan Sheng Wang ◽  
Yun Long Yu
Keyword(s):  
Heating Temperature ◽  
Upconversion Luminescence ◽  
Glass Ceramics ◽  
Upconversion Emission ◽  
Photon Absorption ◽  
Glassy Matrix ◽  
Homogeneous Distribution ◽  
Transparent Glass ◽  
Quenching Effect ◽  
Transition Mechanism

Upconversion luminescence of Er3+-doped SiO2-Al2O3-CaO-NaF-CaF2 transparent glass ceramics under 980 nm excitation was investigated. XRD and TEM experiments revealed the homogeneous distribution of CaF2 nano-crystals among the glassy matrix. Intense red upconversion signal was recorded and its intensity increased with the increasing of heating temperature and Er3+-doping level at the range of 0.1 to 1.0 mol%. When Er3+ doping reached 2 mol%, the concentration quenching effect appeared. All these results could be due to the incorporation of Er3+ ions into precipitated CaF2 nano-crystals. The quadratic pump power dependence of the upconversion luminescence intensity indicated that the transition mechanism of the red emission was due to two-photon absorption processes.

Tuning the upconversion luminescence of cubic KMnF3:Yb3+/Er3+ nanocrystals through inert lanthanide ion doping

2020 ◽  
Vol 8 (8) ◽  
pp. 2847-2851 ◽  
Author(s):  
Yunfei Shang ◽  
Shuwei Hao ◽  
Wei Shao ◽  
Tong Chen ◽  
Yuyan Zhu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Energy Transfer ◽  
Upconversion Luminescence ◽  
Lanthanide Ion ◽  
Ion Doping ◽  
Optical Applications ◽  
Back Transfer ◽  
Upconversion Emissions ◽  
Structure Engineering ◽  
Local Crystal Structure

Efficient tailoring of upconversion emissions in conventional single red emitting KMnF3:Yb3+/Er3+ nanocrystals is achieved through local crystal structure engineering and the suppression of energy transfer as well as back transfer, which is of great significance for extended optical applications.

Charge-transfer in ferromagnesian silicates: The polarized electronic spectra of trioctahedral micas

1972 ◽  
Vol 38 (297) ◽  
pp. 551-563 ◽  
Author(s):  
D. W. Robbins ◽  
R. G. J. Strens
Keyword(s):  
Charge Transfer ◽  
Near Infrared ◽  
Charge Transfer Band ◽  
Visible Region ◽  
Visible Spectrum ◽  
Ferric Ions ◽  
Ferrous Ions ◽  
Near Ultraviolet ◽  
Wide Range ◽  
Transmission Window

SummaryPolarized spectra (2000 to 25000 Å) have been obtained for fifteen analysed trioctahedral micas covering a wide range of compositions, and including four phlogopites, nine biotites, and two lepidomelanes. Three main contributions to the absorption have been noted: charge transfer from oxygen to ferrous iron throughout the visible and near ultraviolet, charge transfer from ferrous to ferric ions at the red end of the visible spectrum and internal d-d transitions of ferrous ions in the near infrared.Substitutions in the brucite layer (especially Ti) cause the O → Fe2+ band to broaden, and thus to encroach on the visible region for vibration directions in the plane of the cleavage flake. The transmission window between these bands is further blocked by the Fe2+ → Fe3+ charge-transfer band, which is polarized in the plane of the flake. The overall effect is to produce very strong absorption throughout the visible region for (β, γ) vibration directions, and relatively weak absorption for α, i.e. the observed very strong pleochroism of biotite.Many features of the spectra of chlorite, amphiboles, and tourmaline, which contain octahedral ions in brucite-like sheets, strips, and fragments respectively, may be interpreted by analogy with biotite.Two types of solid solution effect are described: substitutional broadening, which is responsible for the extension of the O → Fe2+ band into the visible region in biotites and aluminous ortho-pyroxenes, and substitutional intensification, which permits in solid solutions transitions that are forbidden by the conventional selection rules.

Optical Investigations in Er3+/Yb3+ Co-Doped Nanostructured Phosphate Glass Ceramics

2013 ◽  
Vol 798-799 ◽  
pp. 67-70 ◽  
Author(s):  
Xiao Chen Yu ◽  
Ai Bin Hao ◽  
Shao Wei Liang ◽  
Zhong Wang Sun
Keyword(s):  
Phosphate Glass ◽  
Near Infrared ◽  
Glass Ceramics ◽  
Wavelength Region ◽  
Infrared Emission ◽  
Effective Bandwidth ◽  
Ligand Field ◽  
Crystal Lattices ◽  
Upconversion Emissions ◽  
Co Doped

Er3+/Yb3+co-doped transparent phosphate glass ceramics were fabricated and characterized optically. The formation of nanocrystals is confirmed by x-ray diffraction. Stark split near infrared emission peaks of Er3+have been observed in the glass ceramics, and the effective bandwidth increases with increasing annealing temperature. Upconversion emissions of Er3+in the glass ceramics under 975nm wavelength excitation, especially in the green wavelength region, are enhanced. The results can be attributed to the enhancement of ligand field due to incorporation of Er3+ions into the crystal lattices.

Observation of solid-state reaction between a thin yttria film and a (0001) α-alumina substrate

1994 ◽  
Vol 52 ◽  
pp. 644-645
Author(s):  
J. R. Heffelfinger ◽  
C. B. Carter
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Solid State Reaction ◽  
Yttrium Aluminum Garnet ◽  
Secondary Phase ◽  
Ceramic Composites ◽  
Alumina Substrate ◽  
Transmission Electron ◽  
Alumina Fibers ◽  
Optical Applications

Transmission-electron microscopy (TEM), scanning-electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) were used to investigate the solid-state reaction between a thin yttria film and a (0001) α-alumina substrate. Systems containing Y2O3 (yttria) and Al2O3 (alumina) are seen in many technologically relevant applications. For example, yttria is being explored as a coating material for alumina fibers for metal-ceramic composites. The coating serves as a diffusion barrier and protects the alumina fiber from reacting with the metal matrix. With sufficient time and temperature, yttria in contact with alumina will react to form one or a combination of phases shown by the phase diagram in Figure l. Of the reaction phases, yttrium aluminum garnet (YAG) is used as a material for lasers and other optical applications. In a different application, YAG is formed as a secondary phase in the sintering of AIN. Yttria is added to AIN as a sintering aid and acts as an oxygen getter by reacting with the alumina in AIN to form YAG.

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