Characterization of Erbium Doped SiO2 Layers Formed On Silicon By Spark Processing

1997 ◽  
Vol 486 ◽  
Author(s):  
John V. St. John ◽  
Jeffery L. Coffer ◽  
Young Gyu Rho ◽  
Patrick Diehl ◽  
Russell F. Pinizzotto ◽  
...  
Keyword(s):  
Rare Earth ◽  
Porous Silicon ◽  
Porous Si ◽  
Rare Earth Ion ◽  
Temperature Oxidation ◽  
X Ray ◽  
Near Ir ◽  
Erbium Doped ◽  
Er Doped

AbstractDeposition of a rare earth salt layer on a silicon substrate with subsequent spark processing yields a porous Si layer and SiO 2 cap doped with the rare earth ion. We have characterized luminescent Er-doped porous SiO2 on Si by scanning electron microscopy, energy dispersive Xray spectroscopy, as well as visible and near IR photoluminescence (PL) spectroscopies. Energydispersive x-ray maps indicate that the erbium concentration in the porous layer can be controlled by varying the molarity of the erbium solution deposited on the substrate prior to spark processing. Visible PL measurements reveal that the concentration of Er3+ is proportional to the resultant intensity of the visible fluorescence transitions; however, for the near IR fluorescence peak at 1.54 gim, self-quenching due to erbium clustering occurs at higher concentrations. Erbium-doped porous silicon layers can also be obtained by diffusion of an erbium salt into porous silicon formed by anodic etching of Si in hydrofluoric acid. Densification of the porous Si layers through high temperature oxidation after erbium diffusion forms erbium-doped SiO2 layers.

scholarly journals Synthesis and Characterization of Sr2CeO4 Phosphor Doped with Erbium

2010 ◽  
Vol 13 (1-2) ◽  
pp. 17
Author(s):  
K.V.R. Murthy ◽  
K. Suresh ◽  
B. Nageswara Rao ◽  
B. Walter Ratna Kumar ◽  
Ch. Atchyutha Rao ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Sem Analysis ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Rare Earth Ion ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Pl Emission

<p>The present paper reports the Photoluminescence (PL) of the Sr<sub>2</sub>CeO<sub>4</sub> phosphor, singly doped with Erbium rare-earth ion with different concentrations (0.01, 0.1, 0.2, 0.5 and 1%).The phosphor samples were synthesized using the standard solid state reaction technique. The effect of Er dopant on the structural, morphological, and Photoluminescent properties of the samples are studied with X-ray diffraction (XRD), PL and SEM analysis. The PL emission of undoped Sr<sub>2</sub>CeO<sub>4</sub> phosphor was observed at 470 nm with high intensity followed by the primary Er emissions with good intensity at 525, 530, 549, 557 and 565 nm.</p>

Structural Characterization of Porous Silicon Fabricated by Electrochemical and Chemical Dissolution of Si Wafers

1991 ◽  
Vol 256 ◽  
Author(s):  
S. Miyazaki ◽  
T. Yasaka ◽  
K. Okamoto ◽  
K. Shiba ◽  
K. Sakamoto ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Electron Beam Irradiation ◽  
Complete Recovery ◽  
Porous Si ◽  
Beam Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Disordered Structure ◽  
Visible Luminescence

ABSTRACTThe structure of porous silicon exhibiting efficient visible photoluminescence has been characterized by using Fourier transformed infrared absorption, Raman scattering and x-ray diffraction. It is shown that the lattice spacing in the porous Si layer expands by about 0.3% in the direction perpendicular to the surface and also a partially disordered structure is existing. Electron beam irradiation causes desorption of hydrogen and fluorine bonds which terminate the surface, resulting in the quenching of the visible luminescence. The chemical etching of such layer has led to complete recovery of the luminescence intensity as well as the hydrogen and fluorine bonds termination.

scholarly journals The Physico-Chemical and Mineralogical Characterization of Mg-Rich Synthetic Gypsum Produced in a Rare Earth Refining Plant

2021 ◽  
Vol 13 (9) ◽  
pp. 4840
Author(s):  
Fatai Arolu Ayanda ◽  
Mohd Firdaus Mohd Anuar ◽  
Syaharudin Zaibon ◽  
Shamshuddin Jusop
Keyword(s):  
Rare Earth ◽  
Acid Soils ◽  
Acid Neutralization ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Neutralization Capacity ◽  
Acid Neutralization Capacity ◽  
Refining Plant ◽  
Calcium Magnesium

The physical, chemical and mineralogical characterization of the constituents of magnesium-rich synthetic gypsum produced in a rare earth-refining plant located in Gebeng, Pahang, Malaysia was conducted through elemental chemical analysis, scanning electron microscopy with Energy Dispersive X-ray (EDX)-analyzer, thermal analysis, X-ray fluorescence and X-ray diffraction. The crystalline nature of the by-product was studied using FTIR spectroscopy. Elemental analysis confirmed the presence of Ca and Mg, which are essential macronutrients required by plants and this Ca alongside the high pH (9.17) of MRSG may confer on the material a high acid neutralization capacity. From the result, it was observed that the studied by-product is a heterogeneous crystalline material comprising of gypsum (CaSO4.2H2O) and other major components such as calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate) and sulfur. These aggregates may contribute to give an acid neutralization capacity to MRSG. The XRD study of MRSG indicated a high content of gypsum (45.4%), shown by the d-spacing of 7.609 Å (2-theta 11.63) in the diffractogram. The infrared absorption spectra of MRSG indicate close similarities to mined gypsum. The results of the characterization indicated that MRSG has valuable properties that can promote its use in amending soil fertility constraints on nutrient-deficient tropical acid soils.

Structural Systematics of Rare Earth Complexes. VII. Crystal Structure of Bis(2,2'/6',2␛-Terpyridinium) Octaaquaterbium(III) Heptachloride Hydrate

1994 ◽  
Vol 47 (2) ◽  
pp. 391 ◽  
Author(s):  
CJ Kepert ◽  
BW Skeleton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystal ◽  
Structural Characterization ◽  
Title Compound ◽  
Room Temperature ◽  
Chloride Ions ◽  
Full Matrix ◽  
X Ray

The room-temperature single-crystal X-ray structural characterization of the title compound (tpyH2)2[Tb(OH2)8]Cl7.~2⅓H2O is recorded. Crystals are triclinic, Pī , a 17.063(5), b 16.243(3), c 7.878(3) Ǻ, α 84.78(2), β 84.39(3), γ 87.81(2)°, Z = 2 formula units; 3167 'observed' diffractometer reflections were refined by full-matrix least-squares procedures to a residual of 0.057. Notable features of interest of the compound are the 'chelation' of chloride ions by the terpyridinium cations , and the existence of a free [Tb(OH2)8]2+ cation in the presence of an abundance of chloride ions.

scholarly journals Characterization of conichalcite by SEM, FTIR, Raman and electronic reflectance spectroscopy

2005 ◽  
Vol 69 (2) ◽  
pp. 155-167 ◽  
Author(s):  
B. J. Reddy ◽  
R. L. Frost ◽  
W. N. Martens
Keyword(s):  
Near Infrared ◽  
Adsorbed Water ◽  
Reflectance Spectroscopy ◽  
Sem Images ◽  
X Ray ◽  
Near Ir ◽  
Ir Reflectance ◽  
Yavapai County ◽  
Ir Bands

AbstractThe mineral conichalcite from the western part of Bagdad mine, Bagdad, Eureka District, Yavapai County, Arizona, USA has been characterized by electronic, near-infrared (NIR), Raman and infrared (IR) spectroscopy. Scanning electron microscopy (SEM) images show that the mineral consists of bundles of fibres. Calculations based on the results of the energy dispersive X-ray analyses on a stoichiometric basis show the substitution of arsenate by 12 wt.% of phosphate in the mineral. Raman and IR bands are assigned in terms of the fundamental modes of AsO43− and PO43− molecules and are related to the mineral structure. Near-IR reflectance spectroscopy shows the presence of adsorbed water and hydroxyl units in the mineral. The Cu(II) coordination polyhedron in conichalcite can have at best pseudo-tetragonal geometry. The crystal field and tetragonal field parameters of the Cu(II) complex were calculated and found to agree well with the values reported for known tetragonal distortion octahedral complexes.

Characterization of porous silicon layers by grazing- incidence X-ray fluorescence and diffraction

1991 ◽  
Vol 79 (11) ◽  
pp. 923-928 ◽  
Author(s):  
A. Bensaid ◽  
G. Patrat ◽  
M. Brunel ◽  
F. de Bergevin ◽  
R. Hérino
Keyword(s):  
Porous Silicon ◽  
Grazing Incidence ◽  
X Ray

scholarly journals Structural and morphological characterization of rare earth modified lead titanate

Cerâmica ◽  
2007 ◽  
Vol 53 (328) ◽  
pp. 422-447
Author(s):  
F. C. D. Lemos ◽  
D. M. A. Melo ◽  
P. S. de Lima ◽  
C. A. Paskocimas ◽  
E. Longo ◽  
...  
Keyword(s):  
Rare Earth ◽  
Lead Titanate ◽  
Pechini Method ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Crystallite Sizes ◽  
Modifier Cation

Rare earth modified lead titanate powders Pb1-xRExTiO3 (REPT), x = 0.01, 0.05, 0.07 and RE = Yb, Y, were prepared by the Pechini method. The materials were calcined under flowing oxygen at different temperatures from 300 to 700 ºC. Nanostructured REPT were investigated using X-ray diffraction, scanning electron microscopy and surface area analysis (BET). The results suggest that the modifier cation incorporated into the system has notable influence in the microstructure and a notable decrease in the crystallite sizes.

Interfacial Characterization of Mosi2+ X Sic Composite Thin Films on Molybdenum Substrates

1996 ◽  
Vol 458 ◽  
Author(s):  
S. Govindarajan ◽  
J. J. Moore ◽  
T. R. Ohno ◽  
J. Disam
Keyword(s):  
Composite Film ◽  
Composite Films ◽  
Carbon Diffusion ◽  
Detailed Examination ◽  
X Ray Diffraction ◽  
Diffusion Anneal ◽  
Temperature Oxidation ◽  
X Ray ◽  
Diffusion Barrier Layer

ABSTRACTA novel coating architecture is being examined for enhancing the high temperature, oxidation resistance of molybdenum. The coating incorporates a thin, composite film of MoSi2+1.96 mole fraction SiC in order to match the coefficients of thermal expansion between the molybdenum substrate and the coating. Since the as-deposited composite film is amorphous in nature, a diffusion anneal treatment is carried out at 1000°C to achieve crystallization of the film. In this paper, a detailed examination of the Mo-MoSi2+1.96 SiC interface will be presented. The microstructural features of the composite films will be discussed based on electron microscopy, auger electron spectroscopy (AES), and X-ray diffraction analysis. Finally, a novel diffusion barrier layer for minimizing silicon and carbon diffusion from the coating to the substrate will be discussed.

Synthesis, Morphology Control and Luminescent Properties of Rare Earth Ion-Doped CaWO4 Microstructures

2016 ◽  
Vol 16 (4) ◽  
pp. 4029-4034 ◽  
Author(s):  
Chunxia Liu ◽  
Lixia Yang ◽  
Dan Yue ◽  
Mengnan Wang ◽  
Lin Jin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Uv Light ◽  
Luminescent Properties ◽  
Average Diameter ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Rare Earth Ion ◽  
X Ray ◽  
Facile Hydrothermal Route

Rare earth ions (Tb3+, Eu3+) doped CaWO4 microstructures were synthesized by a facile hydrothermal route without using any templates and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectrum. The results indicate that the asprepared samples are well crystallized with scheelite structure of CaWO4, and the average diameter of the microstructures is 2∼4 μm. The morphology of CaWO4:Eu3+ microstructures can be controllably changed from microspheres to microflowers through altering the doping concentration of Eu3+ from 3% to 35%, and the microflowers are constructed by a number of CaWO4:Eu3+ nanoflakes. Under the excitation of UV light, the emission spectrum of CaWO4:Eu3+ is composed of the characteristics emission of Eu3+ 5D0-7FJ (J = 1, 2, 3, 4) transitions, and that of CaWO4:Tb3+ is composed of Tb3+ 5D4-7FJ (J = 6, 5, 4, 3) transitions. Both of the optimal doping concentrations of Tb3+ and Eu3+ in CaWO4 microstructures are about 5%.

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