SAMARIUM ACTIVATED ABSORPTION AND EMISSION OF ZINC TELLURITE GLASS

2016 ◽  
Vol 78 (3-2) ◽  
Author(s):  
Y.A. Tanko ◽  
M.R. Sahar ◽  
S.K. Ghoshal
Keyword(s):  
Rare Earth ◽  
Cross Sections ◽  
Near Infrared ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Absorption And Emission ◽  
Enhanced Absorption ◽  
Nir Absorption ◽  
Dependent Absorption ◽  
The Right

Enhanced absorption and emission cross-sections of rare earth doped binary glasses are highly demanding for various photonic applications. Determining the right glass compositions with appropriate rare earth dopants remain challenging. Different microscopic mechanisms responsible for optical enhancement and quenching are not fully understood. In this view, we prepare a series of glasses with composition (80-x)TeO2-20ZnO-(x)Sm2O3, where 0 ≤ x ≤ 1.5 mol% using melt quenching technique. X-ray diffraction (XRD), Photoluminescence (PL) and Ultraviolet Visible Near-Infrared (UV-Vis-NIR) spectroscopic measurements are carried out to inspect the samarium concentration dependent absorption and emission features of the prepared glasses. Physical properties such as glass density and molar volume are found to be in the range 5.57-5.61 g cm-3 and 25.84-26.15 cm3 mol-1, respectively. XRD pattern verifies the amorphous nature of the prepared samples. The UV-Vis-NIR absorption spectra reveal nine peaks centered at 470, 548, 947, 1085, 1238, 1385, 1492, 1550 and 1589 nm. These bands arise due to 6H5/2→4I11/2, 4G5/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2, and 6F1/2 transitions, respectively. PL spectra under the excitation of 452 nm display four emission bands centered at 563, 600, 644 and 705 nm corresponding to 4G5/2→6H5/2, 6H7/2, 6H9/2 and 6H11/2 transitions of samarium ions. The mechanism of photoluminescence enhancement is identified, analyzed, and understood. A correlation between samarium concentration and optical response is established. This composition may be useful for fabricating various optical devices

Preparation of Heterojunction Semiconductor SnS2/SnO2 with Enhanced Photocatalytic Properties

2013 ◽  
Vol 316-317 ◽  
pp. 1059-1062 ◽  
Author(s):  
Ping Chen ◽  
Ming Sheng Qin ◽  
Fu Qiang Huang
Keyword(s):  
Photocatalytic Activity ◽  
Single Phase ◽  
Near Infrared ◽  
Photocatalytic Performance ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Structure Morphology ◽  
Nir Absorption

The Formation of Heterojunction Structure between Two Semiconductors Was Considered as an Effective Method to Enhance the Photocatalytic Activity. here, we Reported a Simple Method to Prepare SnS2/SnO2Heterojunction Photocatalysts by Annealing SnS2in Air. the Structure, Morphology, Chemical Compositions and Optical Properties of the Obtained Materials Were Characterized by the X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy-dispersive X-ray Spectroscopy (EDX) and Ultraviolet-visible-near Infrared (UV-Vis-NIR) Absorption Spectra. the Photocatalytic Investigations Showed the Composites Have Higher Photocatalytic Activity than the Single-phase SnS2. the SnS2Powder which Annealed at 400 °C for 60 Min Showed the Highest Photocatalytic Performance.

Properties of Rare-Earth Substitution in Bi(Pb)-2223 Superconductor Prepared by Coprecipitation Method

2014 ◽  
Vol 895 ◽  
pp. 83-86
Author(s):  
Jamil Siti Hawa ◽  
Azhan Hashim ◽  
S.Y.S. Yahya ◽  
Azman Kasim ◽  
Hassan Nurul Hidayah ◽  
...  
Keyword(s):  
Rare Earth ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Lanthanide Series ◽  
Oxalate Coprecipitation ◽  
The Right ◽  
Microstructural Examination ◽  
The Eu ◽  
Rare Earth Substitution

The superconducting and structural properties of pure and rare-earth elements substituted in Bi (Pb)-2223 samples were investigated. All samples were fabricated by the oxalate coprecipitation (COP) method using metal acetates and oxalic acid as starting materials. The electrical and resistivity were measured by using the four-probe method, while phase purity and microstructural examination were performed by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM). The pure sample has a critical temperature of (Tc zero) 100 K, which decreased to 98, 96 and 97 K for the Eu, Dy and Yb samples, respectively. At 77 K, the un-doped sample gives the highest Jc, which gradually decreases with rare-earth substitution as one move towards the right in the lanthanide series. XRD results reveal two main phases (Bi-2223 and Bi-2212) with decreased amounts of Bi-2223 phases by rare-earth substitution. SEM micrographs showed flaky grains but Yb showed better grain alignment compared with the other substitutions.

UV-Visible Lasers Based on Rare-Earth Ions

MRS Bulletin ◽  
1999 ◽  
Vol 24 (9) ◽  
pp. 21-26 ◽  
Author(s):  
R. Moncorgé ◽  
L.D. Merkle ◽  
B. Zandi
Keyword(s):  
Rare Earth ◽  
Cross Sections ◽  
Near Infrared ◽  
Yttrium Aluminum Garnet ◽  
Energy Levels ◽  
Wavelength Region ◽  
Rare Earth Ions ◽  
Stimulated Emission ◽  
Laser Materials ◽  
Visible Wavelengths

An issue on novel applications of materials doped with rare-earth (RE) ions can scarcely fail to address lasers, but it need not address all RE-based lasers. Some Nd3+ -doped lasers, particularly Nd:YAG (Y3Al5O12, yttrium aluminum garnet), emitting light with a wavelength of 1064 nm, are very well-established commercial products—by no means novelties.1 Some other near-infrared (NIR) lasers, based on Er3+ or Tm3+, are also available commercially. That wavelength region is relatively easy for RE laser ions, involving energy spacings between initial and final energy levels small enough to give large stimulated emission cross sections for useful, long upper-state life-times, yet large enough to minimize thermal deexcitation mechanisms. On the other hand, RE-doped lasers for ultraviolet (UV) and visible wavelengths are quite novel, since efficient laser operation is more difficult to achieve in these spectral ranges. Intriguing progress on such devices has been made in recent years, driven by several important applications.In this article, we begin by noting some of the alternative ways to obtain laser light at these wavelengths, including their advantages and drawbacks. We then discuss basic properties of RE-doped laser materials and how these can be advantageous. We then review a few of the most important and recent RE-doped laser materials and techniques for obtaining UV and visible output.

Luminescence in Rare Earth Activated AlPO4 Phosphor

2011 ◽  
Vol 306-307 ◽  
pp. 171-175 ◽  
Author(s):  
K.N. Shinde ◽  
S.J. Dhoble
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Solid State Reactions ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Yellow Band ◽  
Xrd Pattern ◽  
X Ray ◽  
Near Ultraviolet

Rare earth activated AlPO4 phosphors were synthesized by solid-state reactions and the completion of the synthesis was confirmed by X-ray diffraction (XRD) pattern. Under near-ultraviolet (nUV) light, the Eu3+ emission in AlPO4 consists of the transitions from 5D0 to 7FJ shows orange/red region and the AlPO4 :Dy3+ phosphor shows an efficient blue and yellow band emissions, which originates from the 4F9/26H15/2 and 4F9/26H13/2 transitions of Dy3+ ion. The excitation spectra of the phosphors are extending from 300 to 400 nm, which are characteristics of nUV excited LED. The effect of the Eu3+ and Dy3+ concentration on the luminescence properties of AlPO4 phosphors is also studied.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

scholarly journals Polyurethane Composite Foams Synthesized Using Bio-Polyols and Cellulose Filler

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3474
Author(s):  
Katarzyna Uram ◽  
Milena Leszczyńska ◽  
Aleksander Prociak ◽  
Anna Czajka ◽  
Michał Gloc ◽  
...  
Keyword(s):  
Cross Sections ◽  
Raw Materials ◽  
Polyurethane Foams ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Polyurethane Composite ◽  
Composite Foams ◽  
Closed Cell ◽  
Ft Ir ◽  
The Fourier Transform

Rigid polyurethane foams were obtained using two types of renewable raw materials: bio-polyols and a cellulose filler (ARBOCEL® P 4000 X, JRS Rettenmaier, Rosenberg, Germany). A polyurethane system containing 40 wt.% of rapeseed oil-based polyols was modified with the cellulose filler in amounts of 1, 2, and 3 php (per hundred polyols). The cellulose was incorporated into the polyol premix as filler dispersion in a petrochemical polyol made using calenders. The cellulose filler was examined in terms of the degree of crystallinity using the powder X-ray diffraction PXRD -and the presence of bonds by means of the fourier transform infrared spectroscopy FT-IR. It was found that the addition of the cellulose filler increased the number of cells in the foams in both cross-sections—parallel and perpendicular to the direction of the foam growth—while reducing the sizes of those cells. Additionally, the foams had closed cell contents of more than 90% and initial thermal conductivity coefficients of 24.8 mW/m∙K. The insulation materials were dimensionally stable, especially at temperatures close to 0 °C, which qualifies them for use as insulation at low temperatures.

scholarly journals High Pressure X-ray Diffraction as a Tool for Designing Doped Ceria Thin Films Electrolytes

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 724
Author(s):  
Sara Massardo ◽  
Alessandro Cingolani ◽  
Cristina Artini
Keyword(s):  
Thin Films ◽  
High Pressure ◽  
Rare Earth ◽  
Ionic Conductivity ◽  
Bulk Material ◽  
Threshold Temperature ◽  
Doped Ceria ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rare Earth Doped

Rare earth-doped ceria thin films are currently thoroughly studied to be used in miniaturized solid oxide cells, memristive devices and gas sensors. The employment in such different application fields derives from the most remarkable property of this material, namely ionic conductivity, occurring through the mobility of oxygen ions above a certain threshold temperature. This feature is in turn limited by the association of defects, which hinders the movement of ions through the lattice. In addition to these issues, ionic conductivity in thin films is dominated by the presence of the film/substrate interface, where a strain can arise as a consequence of lattice mismatch. A tensile strain, in particular, when not released through the occurrence of dislocations, enhances ionic conduction through the reduction of activation energy. Within this complex framework, high pressure X-ray diffraction investigations performed on the bulk material are of great help in estimating the bulk modulus of the material, and hence its compressibility, namely its tolerance toward the application of a compressive/tensile stress. In this review, an overview is given about the correlation between structure and transport properties in rare earth-doped ceria films, and the role of high pressure X-ray diffraction studies in the selection of the most proper compositions for the design of thin films.

scholarly journals High-pressure synthesis of REB5O8(OH)2 (RE = Ho, Er, Tm)

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Michael Zoller ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
Rare Earth ◽  
Ir Spectroscopy ◽  
Earth Metal ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Solution ◽  
Pressure Synthesis ◽  
The Rare Earth

AbstractThe rare earth oxoborates REB5O8(OH)2 (RE = Ho, Er, Tm) were synthesized in a Walker-type multianvil apparatus at a pressure of 2.5 GPa and a temperature of 673 K. Single-crystal X-ray diffraction data provided the basis for the structure solution and refinement. The compounds crystallize in the monoclinic space group C2 (no. 5) and are composed of a layer-like structure containing dreier and sechser rings of corner sharing [BO4]5− tetrahedra. The rare earth metal cations are coordinated between two adjacent sechser rings. Further characterization was performed utilizing IR spectroscopy.

Activatable Rare Earth Near-Infrared-II Fluorescence Ratiometric Nanoprobes

Nano Letters ◽  
2021 ◽  
Author(s):  
Ziqiang Sun ◽  
Haoying Huang ◽  
Rong Zhang ◽  
Xiaohu Yang ◽  
Hongchao Yang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Near Infrared
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