Temperature‐dependent Formation of Ozone in Solid Oxygen by 5 keV Electron Irradiation and Implications for Solar System Ices

2007 ◽  
Vol 669 (2) ◽  
pp. 1414-1421 ◽  
Author(s):  
Bhalamurugan Sivaraman ◽  
Corey S. Jamieson ◽  
Nigel J. Mason ◽  
Ralf I. Kaiser
Keyword(s):  
Solar System ◽  
Electron Irradiation ◽  
Temperature Dependent ◽  
Solid Oxygen

Temperature dependent mid-infrared (5–25 μm) reflectance spectroscopy of carbonaceous meteorites and minerals: Implication for remote sensing in Solar System exploration

Icarus ◽  
2021 ◽  
Vol 354 ◽  
pp. 114040
Author(s):  
Giovanni Poggiali ◽  
John Robert Brucato ◽  
Elisabetta Dotto ◽  
Simone Ieva ◽  
Maria Antonietta Barucci ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Solar System ◽  
Reflectance Spectroscopy ◽  
Temperature Dependent ◽  
Mid Infrared ◽  
Solar System Exploration

scholarly journals Optical properties of electron-irradiated GaN

1998 ◽  
Vol 3 ◽  
Author(s):  
I. A. Buyanova ◽  
Mt. Wagner ◽  
W. M. Chen ◽  
L. Lindström ◽  
B. Monemar ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Electron Irradiation ◽  
Principal Axis ◽  
Host Lattice ◽  
Temperature Dependent ◽  
Crossing Experiments ◽  
Axial Complex ◽  
Internal Transition ◽  
Optically Detected

The electronic structure of defects produced by 2.5-MeV electron irradiation and their effect on optical properties of GaN are investigated using photoluminescence (PL) and optically detected magnetic resonance (ODMR) techniques. The electron irradiation is shown to produce, in particular, a deep PL band with a no-phonon line at around 0.88 eV followed by a phonon-assisted sideband. We suggest that this emission is caused by an internal transition between excited and ground state of a deep defect. The excited state is a multiple-level state, as revealed from temperature dependent PL and level anti-crossing experiments. The electronic structure of the 0.88 eV defect is shown to be sensitive to the internal strain in the GaN epilayers. The ODMR studies reveal that the principal axis of the defect coincides with the c-axis of the host lattice and should therefore be either an on-site point defect or an axial complex defect along the c-axis.

scholarly journals Temperature dependent evolution of dislocation loops in YSZ under high energy electron irradiation

2016 ◽  
Vol 41 (3) ◽  
pp. 319-323 ◽  
Author(s):  
AKM Saiful Islam Bhuian ◽  
Kento Kuwahara ◽  
Tomokazu Yamamoto ◽  
Kazuhiro Yasuda ◽  
Syo Matsumura ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
High Energy ◽  
Energy Electron ◽  
Dislocation Loops ◽  
High Energy Electron ◽  
Temperature Dependent

Comparison of Electron Beam-Induced and Light-Induced Defect Saturation in a-Si:H

1992 ◽  
Vol 258 ◽  
Author(s):  
M. Grimbergen ◽  
A. Lopez-Otero ◽  
A. Fahrenbruch ◽  
L. Benatar ◽  
D. Redfield ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Irradiation ◽  
Defect Density ◽  
Dark Conductivity ◽  
High Light Intensity ◽  
Generation Rate ◽  
Temperature Dependent ◽  
Photon Irradiation ◽  
Temperature Ranges ◽  
Induced Defects

ABSTRACTGeneration, saturation, and annealing characteristics of metastable defects formed by electron beam irradiation at 20 keV and photon irradiation at 1.9 eV have been compared. Saturation density reached by electron irradiation is temperature independent over the range 225 K to 300 K, although a small activation energy of the generation rate may be present. This differs from observed temperature dependent light-induced saturation from 330 K to 470 K, although differences are expected because of the separate temperature ranges and dissimilar carrier excitation rates. The electron beam-induced saturated defect density is about 5 times larger than for light-induced saturation at 350 K and high light intensity (generation rate ≈ 1022cm-3s-1). Defects formed by electron irradiation anneal at 300 K with a stretched exponential time constant three orders of magnitude smaller than for light-induced defects. After electron irradiation, dark conductivity relaxes faster than photoconductivity. Once the dark Fermi level becomes constant during defect density relaxation, photoconductivity is inversely proportional to the defect density.

scholarly journals Acceptors in undoped gallium antimonide

2003 ◽  
Vol 799 ◽  
Author(s):  
M. K. Lui ◽  
C. C. Ling ◽  
X. D. Chen ◽  
K. W. Cheah ◽  
K. F. Li
Keyword(s):  
Electron Irradiation ◽  
Ionization Energy ◽  
Gallium Antimonide ◽  
Temperature Dependent ◽  
Irradiation Dosage ◽  
Radiative Defect ◽  
Related Defect ◽  
P Type ◽  
Two Peaks ◽  
Irradiation Process

ABSTRACTUndoped GaSb materials were studied by temperature dependent Hall (TDH) measurements and photoluminescence (PL). The TDH data reveals four acceptor levels (having ionization energies of 7meV, 32meV, 89meV and 123meV) in the as-grown undoped GaSb samples. The 32meV and the 89meV levels were attributed to the GaSb defect and the VGa-related defect. The GaSb defect was found to be the important acceptor responsible for the p-type nature of the present undoped GaSb samples because of its abundance and its low ionization energy. This defect was thermally stable after the 500°C annealing. Similar to the non-irradiated samples, the 777meV and the 800meV PL signals were also observed in the electron irradiated undoped GaSb samples. The decrease of the two peaks' intensities with respect to the electron irradiation dosage reveals the introduction of a non-radiative defect during the electron irradiation process, which competes with the transition responsible for the 777meV and the 800meV PL peaks.

scholarly journals Vacuum ultraviolet photoabsorption spectroscopy of space-related ices: 1 keV electron irradiation of nitrogen- and oxygen-rich ices

2020 ◽  
Vol 641 ◽  
pp. A154
Author(s):  
S. Ioppolo ◽  
Z. Kaňuchová ◽  
R. L. James ◽  
A. Dawes ◽  
N. C. Jones ◽  
...  
Keyword(s):  
Solar System ◽  
Nitrogen Oxides ◽  
Electron Irradiation ◽  
Vacuum Ultraviolet ◽  
Thermal Evolution ◽  
Absorption Bands ◽  
Cold Surface ◽  
Star Forming ◽  
Before And After ◽  
Physical And Chemical

Context. Molecular oxygen, nitrogen, and ozone have been detected on some satellites of Saturn and Jupiter, as well as on comets. They are also expected to be present in ice-grain mantles within star-forming regions. The continuous energetic processing of icy objects in the Solar System induces physical and chemical changes within the ice. Laboratory experiments that simulate energetic processing (ions, photons, and electrons) of ices are therefore essential for interpreting and directing future astronomical observations. Aims. We provide vacuum ultraviolet (VUV) photoabsorption spectroscopic data of energetically processed nitrogen- and oxygen-rich ices that will help to identify absorption bands and/or spectral slopes observed on icy objects in the Solar System and on ice-grain mantles of the interstellar medium. Methods. We present VUV photoabsorption spectra of frozen O2 and N2, a 1:1 mixture of both, and a new systematic set of pure and mixed nitrogen oxide ices. Spectra were obtained at 22 K before and after 1 keV electron bombardment of the ice sample. Ices were then annealed to higher temperatures to study their thermal evolution. In addition, Fourier-transform infrared spectroscopy was used as a secondary probe of molecular synthesis to better identify the physical and chemical processes at play. Results. Our VUV data show that ozone and the azide radical (N3) are observed in our experiments after electron irradiation of pure O2 and N2 ices, respectively. Energetic processing of an O2:N2 = 1:1 ice mixture leads to the formation of ozone along with a series of nitrogen oxides. The electron irradiation of solid nitrogen oxides, pure and in mixtures, induces the formation of new species such as O2, N2, and other nitrogen oxides not present in the initial ice. Results are discussed here in light of their relevance to various astrophysical environments. Finally, we show that VUV spectra of solid NO2 and water can reproduce the observational VUV profile of the cold surface of Enceladus, Dione, and Rhea, strongly suggesting the presence of nitrogen oxides on the surface of the icy Saturn moons.

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