scholarly journals Ultraluminous X-ray sources. Optical data.

2018 ◽  
Author(s):  
Sergei N. Fabrika
Keyword(s):  
Optical Data ◽  
X Ray

Effect of morphology on supercapacitive and optical properties of chemically grown Graphene-Nickel Oxide nanocomposites

2020 ◽  
Vol 34 (26) ◽  
pp. 2050229
Author(s):  
Fatemeh Zahraei ◽  
Ferydon Babaei ◽  
Ali Ehsani
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Nickel Oxide ◽  
Optical Data ◽  
X Ray ◽  
Capacitive Behavior ◽  
Liquid Phase Exfoliation ◽  
Grown Graphene ◽  
Hydrothermal Methods ◽  
Absorbance Spectra

Graphene-Nickel Oxide (G-NiO) nanocomposites with different morphologies, such as nanowires (NWs), nanorods (NRs) and nanoparticles (NPs), are synthesized by a combination of liquid-phase exfoliation (LPE) and hydrothermal methods. The synthesis of Graphene, morphology of Nickel Oxide (NiO) thin films and concentration of elements are analyzed using Raman Spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) and Energy-dispersive X-ray spectroscopy (EDS), respectively. Furthermore, the capacitive behavior of nanocomposites is investigated using the Cyclic Voltammetry (CV). The optical properties of samples are extracted from measured absorbance spectra. Our results show that G-NiO NWs with the longest length have the largest specific capacitance (SC). In addition, optical data revealed that the adding Graphene to NiO thin films decreased the optical bandgap as well as the optical conductivity of nanocomposites increased with photon energy due to excitation electrons.

X-Ray and Optical Data for a Rare Earth–Poor Eudialyte from the North–Central Alaska Range

1990 ◽  
Vol 5 (2) ◽  
pp. 89-92 ◽  
Author(s):  
Neil E. Johnson ◽  
Mickey E. Gunter ◽  
Diana N. Solie ◽  
Charles R. Knowles
Keyword(s):  
Rare Earth ◽  
Powder Diffraction ◽  
Weight Percent ◽  
Optical Data ◽  
Alaska Range ◽  
North Central ◽  
X Ray ◽  
The North ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

AbstractPowder X-ray and optical data have been recorded for a sample of exceptionally rare earth-poor eudialyte (Na12(Ca, REE)6(Fe2+,Mn,Mg)3Zr3(Zr,Nb)x[Si9O27−y(OH)y]2[Si3O9]2(C1,F)z, with x = 0. 1–0.9, y = 1–3 and z = 0.7–1.4) from a pegmatitic vein associated with the peralkaline Windy Fork granite in the north–central Alaska range. The eudialyte is uniaxial positive with ω= 1.6062(2), ε= 1.6138 (3) and microprobe analyses indicate that the sum of REE + Yis less than 0.1 weight percent. Refined unit cell dimensions are: a = 14.2572(4), c = 30.1338(27), Dx= 2.67, F30= 128 (0.006, 42), M20= 76. An indexed powder diffraction pattern is given.

scholarly journals An X-ray and optical study of the outbursting behaviour of the SMC Be X-ray binary SXP 91.1

2019 ◽  
Vol 489 (1) ◽  
pp. 993-999 ◽  
Author(s):  
I M Monageng ◽  
M J Coe ◽  
J A Kennea ◽  
L J Townsend ◽  
D A H Buckley ◽  
...  
Keyword(s):  
Neutron Star ◽  
Gravitational Lensing ◽  
Optical Data ◽  
Type I ◽  
X Ray ◽  
Spin Period ◽  
Average Spin ◽  
Period Derivative ◽  
Inclination Angles ◽  
Using Data

ABSTRACT In this paper we report on the optical and X-ray behaviour of the Be X-ray binary, SXP 91.1, during a recent type I outburst. We monitored the outburst using the Neil Gehrels Swift Observatory. These data were supported by optical data from the Southern African Large Telescope and the Optical Gravitational Lensing Experiment (OGLE) to show the circumstellar disc activity. Matter from this disc accretes on to the neutron star, giving rise to the X-ray outburst as seen in the synchronous evolution of the optical and X-ray light curves. Using data taken with OGLE we show that the circumstellar disc has exhibited stable behaviour over two decades. A positive correlation is seen between the colour and magnitude from the OGLE and massive compact halo object observations, which indicates that the disc is orientated at relatively low-inclination angles. From the OGLE and Swift data, we demonstrate that the system has shown relative phase offsets that have persisted for many years. The spin period derivative is seen to be at maximum spin-up at phases when the mass accretion rate is at maximum. We show that the neutron star in SXP 91.1 is an unusual member of its class in the sense that it has had a consistent spin period derivative over many years, with the average spin-up rate being one of the highest for known Small Magellanic Cloud pulsars. The most recent measurements of the spin-up rate reveal higher values than the global trend, which is attributed to the recent mass accretion event leading to the current outburst.

Tin-bearing sulphides from St Michael's Mount and Cligga Head, Cornwall

1984 ◽  
Vol 48 (348) ◽  
pp. 389-396 ◽  
Author(s):  
F. Moore ◽  
R. A. Howie
Keyword(s):  
Optical Properties ◽  
Electron Probe ◽  
Optical Data ◽  
X Ray ◽  
Cautious Approach ◽  
South West ◽  
South West England

Abstract The result of electron probe microanalyses, along with X-ray and optical data obtained for tin sulphides from two different localities in south-west England indicate that the mineral hitherto described from St Michael’s Mount as stannite is in fact kesterite, Cu2(Fe0.23Zn0.77)SnS4. The yellow ‘stannite’ reported from this locality proved to be stannoidite, Cu8(Fe2.39 Zn0.61)SnS2S12. Kesterite, Cu2(Fe0.09Zn0.90SnS4, and zincian stannite, Cu2(Fe0.63Zn0.38)SnS4, are also reported from Cligga Head. It is suggested that a more cautious approach should be taken in identifying these tin sulphides solely on their optical properties.

scholarly journals Aluminium incorporation in polar, semi- and non-polar AlGaN layers: a comparative study of x-ray diffraction and optical properties

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Duc V. Dinh ◽  
Nan Hu ◽  
Yoshio Honda ◽  
Hiroshi Amano ◽  
Markus Pristovsek
Keyword(s):  
Room Temperature ◽  
Optical Emission ◽  
Vapour Phase ◽  
Optical Data ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
Vapour Phase Epitaxy ◽  
X Ray ◽  
Metal Organic ◽  
Organic Vapour

Abstract Growth of AlxGa1−xN layers (0 ≤ x ≤ 1) simultaneously on polar (0001), semipolar ($$10\bar{{\rm{1}}}$$ 10 1 ¯ 3) and ($$11\bar{{\rm{2}}}2$$ 11 2 ¯ 2 ), as well as nonpolar ($$10\bar{{\rm{1}}}0$$ 10 1 ¯ 0 ) and ($$11\bar{{\rm{2}}}0$$ 11 2 ¯ 0 ) AlN templates, which were grown on planar sapphire substrates, has been investigated by metal-organic vapour phase epitaxy. By taking into account anisotropic in-plane strain of semi- and non-polar layers, their aluminium incorporation has been determined by x-ray diffraction analysis. Optical emission energy of the layers was obtained from room-temperature photoluminescence spectra, and their effective bandgap energy was estimated from room-temperature pseudo-dielectric functions. Both x-ray diffraction and optical data consistently show that aluminium incorporation is comparable on the polar, semi- and non-polar planes.

scholarly journals Non-Equilibrium Ionization in Puppis A

1983 ◽  
Vol 101 ◽  
pp. 245-252
Author(s):  
P. F. Winkler ◽  
C. R. Canizares ◽  
B. C. Bromley
Keyword(s):  
High Resolution ◽  
Spectroscopic Data ◽  
Supernova Remnant ◽  
Optical Data ◽  
Equilibrium Conditions ◽  
X Ray ◽  
Flux Measurements ◽  
Far From Equilibrium ◽  
Einstein Observatory ◽  
Non Equilibrium

High resolution X-ray spectroscopy of the brightest knot of emission in the Puppis A supernova remnant shows that it is made up of ionizing plasma, far from equilibrium. Flux measurements in several X-ray lines enable us to determine the non-equilibrium conditions: electron temperature, ion populations, and time since the knot was heated by the supernova shock. Imaging and spectroscopic data from the Einstein Observatory together suggest that this knot is a cloud of density about 10 cm−3 which has recently been shocked to a temperature 7 × 106 K. Radio and optical data on the region appear consistent with this picture.

scholarly journals RX J1015.5+0904: A New Polar at the Lower Period Limit

1996 ◽  
Vol 158 ◽  
pp. 229-230
Author(s):  
V. Burwitz ◽  
K. Reinsch ◽  
A. D. Schwope ◽  
K. Beuermann ◽  
S. Mengel ◽  
...  
Keyword(s):  
Orbital Period ◽  
Optical Observations ◽  
Optical Data ◽  
X Ray ◽  
First Results ◽  
Period Limit ◽  
Lower Period

AbstractWe present X-ray and optical observations of the ROSAT discovered polar (AM Her binary) RX J1015.5+0904 and first results of our analysis of the X-ray and optical data. These results indicate a one-pole accretion geometry and an orbital period of P = 79.88 m for this V ~ 17 mag system.

Epitaxial BaTiO3 Thin Films on Different Substrates for Optical Waveguide Applications

1999 ◽  
Vol 597 ◽  
Author(s):  
M. Siegert ◽  
Judit G. Lisoni ◽  
C. H. Lei ◽  
A. Eckau ◽  
W. Zander ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Waveguides ◽  
Rutherford Backscattering Spectrometry ◽  
Optical Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Ion Channeling ◽  
Atomic Force ◽  
Transmission Electron

AbstractIn the process of developing thin film electro-optical waveguides we investigated the influence of different substrates on the optical and structural properties of epitaxial BaTiO3 thin films. These films are grown by on-axis pulsed laser deposition (PLD) on MgO(100), MgAl2O4(100), SrTiO3(100) and MgO buffered A12O3(1102) substrates. The waveguide losses and the refractive indices were measured with a prism coupling setup. The optical data are correlated to the results of Rutherford backscattering spectrometry/ion channeling (RBS/C). X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM). BaTiO3 films on MgO(100) substrates show planar waveguide losses of 3 dB/cm and ridge waveguide losses of 5 dB/cm at a wavelength of 633 nm.

Identification of Transition Metal Sites in Fused SiO2 by X-Ray Absorption Spectroscopy

1985 ◽  
Vol 61 ◽  
Author(s):  
Farrel W. Lytle ◽  
Robert B. Greegor
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Absorption Spectroscopy ◽  
Optical Data ◽  
Site Symmetry ◽  
X Ray ◽  
Hydrolysis Method ◽  
Fused Quartz ◽  
X Ray Absorption ◽  
Good Agreement

ABSTRACTX-ray absorption spectroscopy is used to determine valence and site symmetry for all the 3d transition metals in fused quartz prepared by the flame hydrolysis method. The results are compared with optical data on the same samples with generally good agreement.

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