Cathodoluminescence of Diffusion Layer Synthesized by Coupling of α-Al2O3 and ZnO

2006 ◽  
Vol 11-12 ◽  
pp. 163-166
Author(s):  
Kenichi Suzuki ◽  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata
Keyword(s):  
Zinc Oxide ◽  
Aluminum Oxide ◽  
Diffusion Layer ◽  
The Other ◽  
Energy Dispersive ◽  
X Ray ◽  
Eds Analysis ◽  
Other Hand ◽  
Α Al2o3 ◽  
Zno Ceramics

Alpha aluminum oxide (α-Al2O3) ceramics was coupled and reacted with zinc oxide (ZnO) ceramics at 1200°C for 24 h. Energy dispersive X-ray spectroscopy (EDS) analysis revealed the existence of step-shaped distribution of Al and Zn near the interface between α-Al2O3 and ZnO. Intense ultraviolet (3.75 eV) emission was clearly observed from the layer. On the other hand, very weak emissions were observed outside the layer near the interface. The compound in the layer is considered to be an attractive material for ultraviolet optoelectronics.

Cathodoluminescence of Diffusion Layer Synthesized by Coupling of β-Ga2O3 and ZnO

2006 ◽  
Vol 320 ◽  
pp. 121-124 ◽  
Author(s):  
Kenichi Suzuki ◽  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata
Keyword(s):  
Zinc Oxide ◽  
Diffusion Layer ◽  
Gallium Oxide ◽  
The Other ◽  
Energy Dispersive ◽  
X Ray ◽  
Eds Analysis ◽  
Other Hand ◽  
Zno Ceramics

Beta gallium oxide (β-Ga2O3) ceramics was coupled and reacted with zinc oxide (ZnO) ceramics at 1200oC for 24 h. Energy dispersive X-ray spectroscopy (EDS) analysis revealed the existence of diffusion layer near the interface between β-Ga2O3 and ZnO. Furthermore, the layer showed monochromatic and intense cathodoluminescence (CL) at 3.5 eV. On the other hand, very weak emissions were observed from the out of the layer. The compound in the layer is considered to be an attractive material for ultraviolet optoelectronics.

Cathodoluminescence of Single Phase ZnAl2O4 and Diffusion Layer Synthesized by Coupling of ZnO and α-Al2O3

2007 ◽  
Vol 350 ◽  
pp. 233-236
Author(s):  
Kenichi Suzuki ◽  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata
Keyword(s):  
Diffusion Layer ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Light Emitter ◽  
Eds Analysis ◽  
Α Al2o3 ◽  
And Diffusion ◽  
Zno Ceramics

Zinc oxide (ZnO) ceramics was coupled and reacted with alpha aluminum oxide (α-Al2O3) ceramics at 1200oC for 24 h. SEM observation and energy dispersive X-ray spectroscopy (EDS) analysis revealed the existence of diffusion layer of 10 μm thickness on the α-Al2O3 side of interface between ZnO and α-Al2O3. The diffusion layer is considered to consist of a ZnAl2O4, from the result of XRD. The cathodoluminescence of the diffusion layer was compared with that of zinc aluminate (ZnAl2O4) ceramics synthesized by conventional solid state reaction method. The single phase ZnAl2O4 showed weak emission peaked at 4.6 eV. On the other hand, the diffusion layer showed intense emission peaked at 3.75 eV. The ZnAl2O4 on the α-Al2O3 side of the interface synthesized by coupling of ZnO and α-Al2O3 is considered to be a excellent material as an ultraviolet light emitter.

scholarly journals White Dwarf Masses and Accretion Rates of Recurrent Novae: an X-ray Perspective

2011 ◽  
Vol 7 (S281) ◽  
pp. 186-189
Author(s):  
Koji Mukai ◽  
Jennifer L. Sokoloski ◽  
Thomas Nelson ◽  
Gerardo J. M. Luna
Keyword(s):  
White Dwarf ◽  
Cataclysmic Variables ◽  
The Other ◽  
X Ray ◽  
Other Hand ◽  
Accretion Rates

AbstractWe present recent results of quiescent X-ray observations of recurrent novae (RNe) and related objects. Several RNe are luminous hard X-ray sources in quiescence, consistent with accretion onto a near Chandrasekhar mass white dwarf. Detection of similar hard X-ray emissions in old novae and other cataclysmic variables may lead to identification of additional RNe candidates. On the other hand, other RNe are found to be comparatively hard X-ray faint. We present several scenarios that may explain this dichotomy, which should be explored further.

Difference thermal analysis of crystalline solids by the use of energy-dispersive X-ray diffraction

1983 ◽  
Vol 16 (2) ◽  
pp. 259-263 ◽  
Author(s):  
N. Eisenreich ◽  
W. Engel
Keyword(s):  
Zinc Oxide ◽  
Ammonium Nitrate ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Kinetic Evaluation ◽  
X Ray ◽  
Thermal Gravimetry ◽  
Fully Automatic ◽  
High Or Low Temperature

A method is described to study the structural behavior of solids subjected to various temperature programs. The instrumentation consists of a high- or low-temperature device, a temperature programmer, a system for energy-dispersive X-ray diffraction and a data processing and storing unit and allows the fully automatic acquisition of series of spectra. A strong data reduction is performed by summing up difference diagrams. Plotting the resulting values versus temperature yields curves comparable to those obtained by differential scanning calorimetry (DSC) or thermal gravimetry (TG). A kinetic evaluation as used in the case of DSC or TG curves is possible. The method was applied to study the thermal behavior of a mixture of ammonium nitrate with zinc oxide. The curves indicate the strong anisotropic thermal expansion of the ammonium nitrate phase IV below 323 K, its transition to phase II at 325–329 K and the solid-state reaction with zinc oxide within the temperature interval of 353–383 K.

Synthesis of ZrO2 Nanotubes by Anodization of Zr Foil

2015 ◽  
Vol 799-800 ◽  
pp. 125-129
Author(s):  
Mary Donnabelle L. Balela ◽  
April Alexa S. Lagarde ◽  
Stephen Jann A. Tamayo ◽  
Nikko S. Villareal ◽  
Ann Marielle Parreno
Keyword(s):  
Aqueous Solution ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Preparation ◽  
The Other ◽  
Preparation Methods ◽  
X Ray ◽  
Anodization Time ◽  
Other Hand ◽  
Scanning Electron

Zirconia (ZrO2) nanotubes were synthesized by anodization of zirconium (Zr) foil in NH4Fand (NH4)2SO4 aqueous solution. Different surface preparation methods (electropolishing and etching) were applied on the Zr foil prior to anodizaton. In addition, the anodization time and NH4F concentration were varied. The structure and morphologies of the nanotubes and their crystallinity were confirmed using scanning electron microscope and x-ray diffractometer, respectively. ZrO2 nanotubes with large diameters and thick walls were formed at lower NH4F concentration and longer anodization time. On the other hand, smaller nanotubes with thinner walls were produced when the NH4F concentration was increased. The synthesized nanotubes were predominantly tetragonal ZrO2 with small amounts of monoclinic ZrO2.

Distribution of Calcium and Phosphate in Cells of the Enamel Organ in the Rat Lower Incisor

1987 ◽  
Vol 1 (2) ◽  
pp. 236-244 ◽  
Author(s):  
T. Kawamoto ◽  
M. Shimizu
Keyword(s):  
The Other ◽  
Whole Body ◽  
Enamel Organ ◽  
Maturation Stage ◽  
Lower Incisor ◽  
X Ray ◽  
Other Hand ◽  
Freeze Dried ◽  
Significant Difference ◽  
Cell Layers

The distribution of calcium and phosphate in the cells of the enamel organ of the rat lower incisors was investigated by autoradiography and energy-dispersive x-ray spectrometry (EDS). Radioactive calcium or phosphate was injected i.p. into seven-day-old rats of the Wistar strain. The animals were frozen 0.5, 1, and 10 min after injection, and embedded in 5% carboxymethyl cellulose. Sagittal sections of 10 μm thickness were made in which the lower incisor was included as a part of the whole-body section. For autoradiography, the sections were freeze-dried and placed in contact with dry thin films prepared from autoradiographic emulsion. For EDS, sections were mounted on carbon stubs, freeze-dried, coated with carbon, and examined by EDS in a SEM. 45Ca and 32P autoradiograms showed that the radioactivity was located over the papillary layer cells adjacent to the secretory stage ameloblasts and was much higher here than in the ameloblastic layer. On the other hand, there was no significant difference between the amount of radioactivity of these two cell layers in the maturation stage, although higher radioactivity was detectable in the maturation stage enamel than in the secretory stage enamel. Pronounced Ka x-ray peaks were obtained for P, S, Cl, and K originating from the cells of the papillary and ameloblastic layers in the secretory stage, but only very low peaks were obtained for Ca. On the other hand, in addition to these elements, remarkably high Ca and Fe peaks could be detected in the ameloblastic layer of the maturation stage.

scholarly journals Year-scale Morphological Variation of the X-ray Crab Nebula

2004 ◽  
Vol 218 ◽  
pp. 181-184 ◽  
Author(s):  
Koji Mori ◽  
David N. Burrows ◽  
George G. Pavlov ◽  
J. Jeff Hester ◽  
Shinpei Shibata ◽  
...  
Keyword(s):  
Morphological Variation ◽  
Crab Nebula ◽  
The Other ◽  
X Ray ◽  
Morphological Variations ◽  
Other Hand ◽  
Pulsar Wind ◽  
Circular Structures ◽  
The Crab Nebula

We present year-scale morphological variations of the Crab Nebula revealed by the Chandra X-ray Observatory. Observations have been performed about every 1.7 years over the three years from launch. The variations are clearly recognized at two sites: the torus and the southern jet. The torus, which had been steadily expanding until 1.7 years ago, now appears to have shrunk in the latest observation. Additionally, the circular structures seen to the northeast of the torus have decayed into several arcs. On the other hand, the southern jet shows the growth of its overall kinked-structure. We discuss the nature of these variations in terms of the pulsar wind nebula mechanism.

scholarly journals Scanning Electron Microscopy–Energy-Dispersive X-ray Spectrometry (SEM–EDS) Analysis of PM1–2 Microspheres Located in Coal Char Particles with Different Morphologies

2020 ◽  
Vol 34 (7) ◽  
pp. 8848-8856
Author(s):  
Elena V. Fomenko ◽  
Vladimir V. Yumashev ◽  
Sergey V. Kukhtetskiy ◽  
Anatoliy M. Zhizhaev ◽  
Alexander G. Anshits
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Coal Char ◽  
Energy Dispersive ◽  
X Ray ◽  
Eds Analysis ◽  
Scanning Electron

Configuration of Quadrivalent Atoms

1929 ◽  
Vol 25 (2) ◽  
pp. 219-221
Author(s):  
T. M. Lowry
Keyword(s):  
The Other ◽  
Tetrahedral Configuration ◽  
X Ray ◽  
Metallic Atom ◽  
Other Hand ◽  
Function Change ◽  
The One ◽  
Image Position ◽  
Octahedral Configuration ◽  
As If

Two alternative views have been expressed in regard to the configuration of quadrivalent atoms. On the one hand le Bel and van't Hoff assigned to quadrivalent carbon a tetrahedral configuration, which has since been confirmed by the X-ray analysis of the diamond. On the other hand, Werner in 1893 adopted an octahedral configuration for radicals of the type MA6, e.g. inand then suggested that “the molecules [MA4]X2 are incomplete molecules [MA6]X2. The radicals [MA4] result from the octahedrally-conceived radicals [MA6] by loss of two groups A, but with no function-change of the acid residue…. They behave as if the bivalent metallic atom in the centre of the octahedron could no longer bind all six of the groups A and lost two of them leaving behind the fragment [MA4]” (p. 303).

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