Analysis of luminescence of Eu3+ doped Lu2Ti2O7 powders with Judd-Ofelt theory

Abstract Eu3+ doped Lu2Ti2O7 particles of 6 to 10 nm in diameter are prepared by Pechini-type polymerized complex route based on polyesterification between citric acid (CA) and ethylene glycol. X-ray diffraction measurements confirmed that Eu3+ doped Lu2Ti2O7 powders crystallized in the face-centered cubic lattice (Fd3m). Emission spectra displayed characteristic 5D0 →7 FJ (J = 0, 1, 2, 3 and 4) spin forbidden f-f electronic transitions of the Eu3+ ions with the most pronounced emission coming from 5D0 →7 F2 and with the emission decays varying between 0.75 and 0.60 ms for samples doped with different concentration of Eu3+. The Judd-Ofelt theory was applied to the experimental data for the quantitative determination of optical parameters such as Ω2, Ω4 Judd-Ofelt parameters, radiative and nonradiative transition rates and emission quantum efficiency. It was observed that, for all the samples, Ω2 >> Ω4. The luminescence quantum yields were calculated by means of the Judd-Ofelt theory and the highest value 60.83 % is obtained for particles doped with concentration of 3 % Eu3+.

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Controlling Aspect Ratio of Copper Group Nanowire Arrays by Electrochemical Deposition in the Nanopores of AAO

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.429 ◽

2011 ◽

Vol 335-336 ◽

pp. 429-432 ◽

Cited By ~ 3

Author(s):

Xiu Yu Sun ◽

Fa Qiang Xu

Keyword(s):

Aspect Ratio ◽

Nanowire Arrays ◽

Face Centered Cubic ◽

X Ray Diffraction ◽

X Ray ◽

Anodic Aluminum ◽

Au Nanowire ◽

The Face ◽

Face Centered ◽

Xrd Patterns

Highly ordered Cu, Ag and Au nanowire arrays with high aspect ratio and highly dense self-supporting nanowire patterns of copper group were successfully prepared using cyclic voltammetry with the assistance of anodic aluminum oxide (AAO) template. The X-ray diffraction (XRD) patterns of the metal nanowries were indexed to the face-centered cubic structure. The field emission scanning electron microscope (FE-SEM) results demonstrated that the length of nanowire could be controlled by changing the electrodepositon conditions. The aspect ratio of nanowire arrays can be tuned.

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Experimental Determination of Dissolution Kinetics of Zr-Substituted Gd-Ti Pyrochlore Ceramics: Influence of Chemistry on Corrosion Resistance

MRS Proceedings ◽

10.1557/proc-757-ii6.1 ◽

2002 ◽

Vol 757 ◽

Author(s):

Icenhower J.P. ◽

Weber W.J. ◽

Hess N.J. ◽

Thevuthasen S. ◽

Begg B.D. ◽

...

Keyword(s):

Corrosion Resistance ◽

Dissolution Kinetics ◽

Fluorite Structure ◽

Annealed Specimen ◽

Face Centered Cubic ◽

Zirconium Content ◽

The Face ◽

Flow Through ◽

Face Centered

ABSTRACTThe corrosion resistance of a series of zirconium-substituted gadolinium pyrochlore, Gd2(Ti1-x Zrx)2O7, where x = 0.0, 0.25, 0.50, 0.75, and 1.00, were evaluated using single-pass flow-through (SPFT) apparatus at 90°C and pH = 2. The zirconate end-member, Gd2Zr2O7, has a defect fluorite structure, which distinguishes it from the face-centered cubic structure of the true pyrochlore specimens. In addition to the chemical variation, the samples include annealed, un-annealed, and ion-bombarded monoliths. In the case of the titanate end-member, Gd2Ti2O7, the annealed specimen exhibited the least reactivity, followed by the un-annealed and ion-bombarded samples (2.39×10-3, 1.57×10-2, and 1.12×10-1 g m-2 d-1, respectively). With increasing zirconium content, the samples displayed less sensitivity to processing or surface modification with the zirconate end-member exhibiting no difference in reactivity between annealed, un-annealed, and ion-bombarded specimens (rate = 4.0×10-3 g m-2 d-1). In all cases, the dissolution rate decreased with increasing zirconium content to the Gd2(Ti0.25Zr0.75)2O7 composition (1.33x10-4 g m-2 d-1), but the zirconate end-member yielded rates nearly equal to that of the titanate end-member. These results demonstrate that to achieve the greatest radiation and corrosion resistance in this series, the Gd2(Ti0.25Zr0.75)2O7 composition should be considered.

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Preparation and Characterization of porous Carbon/Nickel Nanofibers for Supercapacitor

Journal of Engineered Fibers and Fabrics ◽

10.1177/155892501300800405 ◽

2013 ◽

Vol 8 (4) ◽

pp. 155892501300800 ◽

Cited By ~ 2

Author(s):

Dawei Gao ◽

Lili Wang ◽

Xin Xia ◽

Hui Qiao ◽

Yibing Cai ◽

...

Keyword(s):

Carbon Nanofibers ◽

Porous Carbon ◽

Composite Nanofibers ◽

Face Centered Cubic ◽

X Ray Diffraction ◽

Nickel Particles ◽

The Face ◽

Embedded Particles ◽

Face Centered

Two polymer solutions of polyacrylonitrile, polyvinyl pyrrolidone, and Ni(CH3COOH)2 in dimethylformamide were electrospun into ternary composite nanofibers, followed by stabilization and carbonization processes to obtain porous carbon/nickel composite nanofibers with diameters of 100–200 nm. The study revealed that carbon/nickel composite nanofibers were successfully prepared, which allowed nickel particles with diameters of 20–70 nm to be uniformly distributed in the carbon nanofibers. It was also observed that the fibrous structures with particles embedded formed and the fibers broke into shorter fibers after sintering. X-ray diffraction indicated that embedded particles crystallized with the face centered cubic structure. The Brunauer-Emmett-Teller analysis revealed that carbon/nickel composite nanofibers with meso-pores possessed larger specific surface area than that of carbon nanofibers. The specific capacitance of the composite nanofiber electrode was as high as 103.8 F/g and showed stable cyclicity (73.8%).

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The determination of solute atom displacements in mixed dumbbell interstitials for the face-centered-cubic lattice

Canadian Journal of Physics ◽

10.1139/p78-138 ◽

1978 ◽

Vol 56 (8) ◽

pp. 1057-1070 ◽

Cited By ~ 43

Author(s):

N. Matsunami ◽

M. L. Swanson ◽

L. M. Howe

Keyword(s):

Solute Atom ◽

The Body ◽

Continuum Approximation ◽

Face Centered Cubic ◽

Cubic Lattice ◽

The Face ◽

Solute Atoms ◽

Face Centered ◽

Small Solute

Interactions between irradiation-produced defects and solute atoms in metals have been investigated using the channeling technique. The interaction of interest in this investigation is the trapping of self interstitials by small solute atoms thus creating a [Formula: see text] mixed dumbbell, consisting of a host atom and a solute atom straddling a lattice site in the face-centered-cubic lattice. The displacement of solute atoms from lattice sites in the mixed dumbbell configuration was determined by comparing the experimentally observed normalized yields from solute atoms and from host atoms with the yields calculated analytically using the continuum approximation. The solute atoms in Al–Mn, Al–Cu, and Cu–Be mixed dumbbells were situated at 0.5 Å from the body-centered position, whereas the Ag atoms in Al–Ag dumbbells were 0.7 Å from this position. This result is consistent with the theoretical expectation that the smallest solute atoms are displaced the greatest amount in mixed dumbbells. In addition, experimentally obtained solute atom yields for [Formula: see text] and [Formula: see text] angular scans were compared with calculated scans. It was concluded that for large displacements of solute atoms into the flux peaking region, the analytical (continuum) calculation is a reliable method of determining solute atom displacements, either from the aligned yields or from the angular scans.

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Formation of face-centered cubic titanium on a Ni single crystal and in Ni/Ti multilayers

Journal of Materials Research ◽

10.1557/jmr.1994.0031 ◽

1994 ◽

Vol 9 (1) ◽

pp. 31-38 ◽

Cited By ~ 52

Author(s):

Alan F. Jankowski ◽

Mark A. Wall

Keyword(s):

Structural Characteristics ◽

Single Layer ◽

High Resolution Electron Microscopy ◽

Cubic Phase ◽

Face Centered Cubic ◽

X Ray Diffraction ◽

X Ray ◽

Resolution Electron ◽

The Face ◽

Face Centered

The artificial layering of metals can change both physical and structural characteristics from the bulk. The stabilization of polymorphic metallic phases can occur on a dimensional scale that ranges from single overgrowth layers to repetitive layering at the nanoscale. The sputter deposition of crystalline titanium on nickel, as both a single layer and in multilayer form, has produced a face-centered cubic phase of titanium. The atomic structure of the face-centered cubic titanium phase is examined using high resolution electron microscopy in combination with electron and x-ray diffraction.

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Preparation and Characterization of the Ordered SiO2 Colloidal Crystallization Films

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.1389 ◽

2008 ◽

Vol 368-372 ◽

pp. 1389-1391 ◽

Cited By ~ 1

Author(s):

Shuan Gui Qing ◽

Bo Liu ◽

Xun Liang ◽

Hai Yang Li ◽

Wei Zhong Lv ◽

...

Keyword(s):

Self Assembly ◽

Face Centered Cubic ◽

X Ray Diffraction ◽

Assembly Method ◽

Colloidal Crystallization ◽

The Face ◽

Infrared Spectrometer ◽

Face Centered ◽

Sio2 Spheres

Multilayer SiO2 crystals modified by alkoxysilanes were fabricated by the vertical deposition technique combined with self-assembly method. The SiO2 colloidal crystallization was prepared by the traditional Stöber-Fink-Bohn method, and modified by different alkoxysilanes to investigate the properties of the films. The films fabricated by the ordering of SiO2 spheres were investigated by infrared spectrometer, X-ray diffraction, scanning electron microscope, UV-visible spectrophotometer. The results showed that thin film is the face-centered cubic structures and the spheres are [111]-oriented.

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Highly Oriented Co Soft Magnetic Films on Si Substrates

MRS Proceedings ◽

10.1557/proc-562-27 ◽

1999 ◽

Vol 562 ◽

Cited By ~ 3

Author(s):

Heng Gong ◽

Wei Yang ◽

Maithri Rao ◽

David E. Laughlin ◽

David N. Lambeth

Keyword(s):

Magnetic Properties ◽

Magnetic Films ◽

Face Centered Cubic ◽

X Ray Diffraction ◽

Orientation Relationships ◽

Soft Magnetic ◽

X Ray ◽

Si Substrates ◽

The Face ◽

Face Centered

ABSTRACTThin Co and Co based alloy films with the face centered cubic (FCC) structure have been epitaxially grown on single crystal Si wafers by sputter deposition. Epitaxial orientation relationships have been determined by x-ray diffraction, x-ray pole figure scans and TEM. Magnetic properties have been characterized using vibrating sampling magnetometer (VSM), torque magnetometer and BH loop tracer. Soft magnetic properties have been observed for the pure Co films.

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A partly disordered 2 × 2 × 2 – superstructure of γ-brass related phase in Mn–Ni–Zn system

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1515/zkri-2021-2004 ◽

2021 ◽

Vol 236 (3-4) ◽

pp. 71-80

Author(s):

Sivaprasad Ghanta ◽

Anustoop Das ◽

Rajat Kamboj ◽

Partha P. Jana

Keyword(s):

Crystal Structure ◽

High Symmetry ◽

Face Centered Cubic ◽

X Ray Diffraction ◽

X Ray ◽

Lattice Constants ◽

Cubic Lattice ◽

The Face ◽

Face Centered ◽

Related Phase

Abstract The T phase in the Mn–Ni–Zn system was obtained as a product of high-temperature solid-state syntheses from the loaded composition of MnxNi2−xZn11 (x = 0.2–1.5)/MnxNi15.38−xZn84.62 (x = 1.54–11.54). The crystal structure of the T phase has been explored by means of X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The structures were solved in the face-centered cubic space group F 4 ‾ 3 m $F‾{4}3m$ (216) and contain 409–410 atoms/unit cell. The lattice constants were found to be a = 18.1727(2) and 18.1954(1) Å for crystals C1 and C2, respectively. The crystal structure denoted the T phase is a (2aγ)3-superstructure of the ordinary cubic γ-brass-type phase. The phase is isostructural to (Fe, Ni)Zn6.5. A “cluster” description has been used to visualize the crystal structure of the title phase. The structures have been constructed by the five distinct clusters and they are situated about the high symmetry sites of the face-centered cubic lattice. The T phase is stabilized at a valance electron concentration of 1.78, which is slightly higher than those expected for typical γ-brass Hume‐Rothery compounds.

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