scholarly journals Synthesis and photoluminescence properties of Ba2Y3(SiO4)3F:Tm3+ blue-emitting fluorosilicate phosphors

2020 ◽  
Vol 185 ◽  
pp. 04051
Author(s):  
Junhui Yang ◽  
Huanyou Wang ◽  
Jinhua Liu ◽  
Jun Chen ◽  
Fanhua Zeng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Concentration Quenching ◽  
Photoluminescence Properties ◽  
Quenching Mechanism ◽  
Multipole Interaction ◽  
Phase Purity ◽  
X Ray ◽  
Chromaticity Coordinates ◽  
Scanning Electron

Various novel Ba2Y3(SiO4)3F:Tm3+ blue-emitting fluorosilicate materials were achieved via solid-state synthesis. The structure and phase purity of prepared Ba2Y3(SiO4)3F:xTm3+ (x = 0.001-0.10 mol) were examined by X-ray powder diffraction. The surface morphology of Ba2Y3(SiO4)3F:0.01Tm3+ was studied by scanning electron microscopy. Photoluminescence properties were systematically explored under the monitoring emission (λem = 468 nm) and excitation (λex = 302 nm) spectra. The optimum mole ratio of as-synthesized phosphors was 0.01 mol. The concentration quenching mechanism in the Ba2Y3(SiO4)3F host was due to electric multipole interaction. Particularly, the chromaticity coordinates (0.1334, 0.0474) of Ba2Y3(SiO4)3F:0.01Tm3+ are near to those of the commercial BaMgAl10O17:Eu2+. These results validated the Ba2Y3(SiO4)3F:Tm3+ fluorosilicate phosphor can be used as a good blue-emitting candidate for W-LEDs.

scholarly journals Preparation and luminescence properties of Tm3+-doped SrBi2Ta2O9 blue-emitting phosphor

2021 ◽  
Vol 261 ◽  
pp. 02080
Author(s):  
Jianhua Li ◽  
Jinyu Huang ◽  
Jing Liao ◽  
Jinjin Fu ◽  
Bin Deng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Concentration Quenching ◽  
Photoluminescence Properties ◽  
Quenching Mechanism ◽  
Multipole Interaction ◽  
Phase Purity ◽  
X Ray ◽  
Chromaticity Coordinates ◽  
Scanning Electron

Various novel SrBi2Ta2O9:Tm3+ blue-emitting materials were achieved via solid-state synthesis. The structure and phase purity of prepared SrBi2Ta2O9:xTm3+ (x = 0.005-0.30 mol) were examined by X-ray powder diffraction. The surface morphology of SrBi2Ta2O9:0.01Tm3+ were studied by scanning electron microscopy. Photoluminescence properties were systematically explored under the monitoring emission (λem = 468 nm) and excitation (λex = 303 nm) spectra. The optimum mole ratio of as-synthesized phosphors was 0.01 mol. The concentration quenching mechanism in the SrBi2Ta2O9 host was due to electric multipole interaction. Particularly, the chromaticity coordinates (0.1334, 0.0474) of SrBi2Ta2O9:0.01Tm3+ are near to those of the commercial BaMgAl10O17:Eu2+. These results validated the SrBi2Ta2O9:Tm3+ phosphor can be utilized good blue-emitting candidate for W-LEDs.

scholarly journals Synthesis, characterization and photoluminescence properties of Tm3+-doped Ca2YTaO6 blue-emitting phosphors

2021 ◽  
Vol 267 ◽  
pp. 02018
Author(s):  
Jianhua Li ◽  
Jinyu Huang ◽  
Jing Liao ◽  
Jinjin Fu ◽  
Bin Deng
Keyword(s):  
Doping Concentration ◽  
Morphological Characteristics ◽  
Concentration Quenching ◽  
Photoluminescence Properties ◽  
Quenching Mechanism ◽  
Solid State Method ◽  
Multipole Interaction ◽  
X Ray ◽  
State Method ◽  
Scanning Electron

A series of Ca2YTaO6: Tm3+ blue-emitting phosphors were firstly prepared by the solid-state method. The phase formations and purity of Ca2YTaO6: xTm3+ (x = 0.3%-5% mol) were verified by X-ray powder diffraction. The morphological characteristics of Ca2YTaO6: 0.005Tm3+ were detected by scanning electron microscopy (SEM). Photoluminescence properties were discussed by emission (λem = 460 nm) and excitation (λex = 359 nm) spectra. The critical doping concentration of the products was 0.005 mol. The proposed concentration quenching mechanism in Ca2YTaO6 materials was the electric multipole interaction. Besides, the color coordinates (0.1408, 0.0891) of Ca2YTaO6: 0.005Tm3+ were located in blue region. The results suggested the Ca2YTaO6: Tm3+ phosphors can be promising blue-emitting components for the WLED applications.

Phase Development and Dielectric Properties of 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3 Ceramic

2011 ◽  
Vol 700 ◽  
pp. 58-62
Author(s):  
Rachanusorn Roongtao ◽  
Supagorn Rugmai ◽  
Wanwilai C. Vittayakorn
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Factor ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Phase Development ◽  
Scanning Electron

The 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3ceramics has been synthesized through a conventional mixed-oxide by using BT nanopowder and BMN micropowder. The phase purity of the powders and the ceramics was examined using X-ray diffraction (XRD). The 0.98BT-0.02BMN powders were sintered to 92% of the theoretical density at a temperature of 1300 °C for 2 h. The microstructure of the sintered surface was investigated using scanning electron microscopy (SEM). The dielectric constant (εr) and loss factor (tanδ) of the sintered pellets at Curie temperture were 3000 and 0.015, respectively.

Synthesis and Photoluminescence of Rhombic NaLa(MoO4)2:Ln3+ Nanocrystals

2016 ◽  
Vol 16 (4) ◽  
pp. 3617-3621 ◽  
Author(s):  
Yuping Wang ◽  
Mingxia Li ◽  
Kai Pan ◽  
Rong Li ◽  
Naiying Fan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Luminescence Intensity ◽  
Dopant Concentration ◽  
Emission Spectra ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Rhombic NaLa(MoO4)2:Ln3+ (Ln = Eu and Tb) nanocrystals were synthesized by a hydrothermal method. The structures and morphologies of the nanocrystals were characterized by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The results indicated that the crystalline size increased with increasing Na2MoO4 content. The photoluminescence properties of NaLa(MoO4)2:Ln3+ nanocrystals were investigated in detail. In the emission spectra of NaLa(MoO4)2:Eu3+ nanocrystals, the 5D0 → 7F2 is dominant, and the peak positions and spectral shapes of emissions were independent of Eu3+ concentration. The luminescence intensity increased with increasing Eu3+ concentration, up to about 10 mol%, and then decreased. In the emission spectra of NaLa(MoO4)2:Tb3+ nanocrystals, the 5D4 → 7F5 is dominant. The sample with a dopant concentration of 20 mol% showed the highest emission intensity.

Preheating Effects on Bi2S3 Morphology Synthesized via Hydrothermal Method

2013 ◽  
Vol 631-632 ◽  
pp. 298-302
Author(s):  
Xi Liang Chen ◽  
Kai Yan ◽  
Hong Ying Chu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
Great Effort ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Phase ◽  
Hydrothermal Approach ◽  
Scanning Electron

Bi2S3nanorod, nanobelt and flowerlike patterns were synthesized via a facile hydrothermal approach without using any surfactant and acid. The morphology, structure, phase composition, and photoluminescence properties of the as-prepared Bi2S3products were characterized using various techniques (scanning electron microscopy, X-ray diffraction, and photoluminescence spectroscopy). The experimental results showed that the preheating process had a great effort on the morphology of the product.

Influences of Reaction Conditions on the Morphology and Properties of CaWO4 Films Prepared by Anodization

2014 ◽  
Vol 809-810 ◽  
pp. 654-659
Author(s):  
Jian Ling Zhao ◽  
Yong Liao ◽  
Li Ye Zhao ◽  
Xiao Jing Yang ◽  
Wei Yu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photoluminescence Intensity ◽  
Constant Voltage ◽  
Photoluminescence Properties ◽  
Reaction Conditions ◽  
X Ray ◽  
Anodization Method ◽  
Scanning Electron

CaWO4 films were prepared in saturated Ca(OH)2 solution through constant-voltage anodization method. Influences of reaction time, voltage and temperature on the morphology, crystal structure and photoluminescence properties were studied through scanning electron microscopy (SEM), X-ray diffractometer (XRD) and photoluminescence measurements (PL). Results show that the as-prepared CaWO4 film is of tetragonal phase, the reaction conditions affect the morphology, grain size and photoluminescence properties greatly. The CaWO4 film anodized at 20V, 45°C for 40 min is flat, uniform and dense with stronger photoluminescence intensity. The formation process of CaWO4 films has also been discussed.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Scanning Electron Microscopy and X-Ray Analyses of Dental Tissues from a Hibernator

1976 ◽  
Vol 34 ◽  
pp. 178-179
Author(s):  
M. L. Zimny ◽  
A. C. Haller
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Body Temperature ◽  
Ground Squirrel ◽  
Alveolar Bone ◽  
X Ray ◽  
Dental Tissues ◽  
Bone Minerals ◽  
Apical Tooth ◽  
Scanning Electron

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

1995 ◽  
Vol 53 ◽  
pp. 692-693
Author(s):  
Yun Lu ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Morphological Development ◽  
Early Hydration ◽  
X Ray ◽  
Blended Cements ◽  
Powder Particles ◽  
Chemical Wastes ◽  
Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

Defects of Platelet Function Recognized by X-Ray Imaging and Scanning Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 610-613
Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Biology ◽  
Imaging Technique ◽  
Human Platelets ◽  
X Rays ◽  
X Ray ◽  
X Ray Imaging ◽  
Complex Phenomena ◽  
Scanning Electron

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).

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