Electron irradiation induced molecular changes in PMMA : A positron spectroscopy study

2020 ◽  
Author(s):  
Somia Awad ◽  
Tahani Alkureda ◽  
Esam E. Abdel‐Hady ◽  
Mahmoud M. Gomaa
Keyword(s):  
Electron Irradiation ◽  
Spectroscopy Study ◽  
Molecular Changes ◽  
Positron Spectroscopy

Quantitative tunneling spectroscopy study of molecular structural changes due to electron irradiation

1976 ◽  
Vol 14 (4) ◽  
pp. 1437-1446 ◽  
Author(s):  
Mihir Parikh ◽  
James T. Hall ◽  
Paul K. Hansma
Keyword(s):  
Electron Irradiation ◽  
Structural Changes ◽  
Tunneling Spectroscopy ◽  
Spectroscopy Study

Defects in PbTe doped with telluride VTe2: Positron spectroscopy study

2010 ◽  
Vol 64 (6) ◽  
pp. 661-663 ◽  
Author(s):  
A.A. Vinokurov ◽  
V.P. Zlomanov ◽  
M. Elsayed ◽  
R. Krause-Rehberg
Keyword(s):  
Spectroscopy Study ◽  
Positron Spectroscopy

A Tunneling Spectroscopy Study of Molecular Degradation due to Electron Irradiation

Science ◽  
1975 ◽  
Vol 188 (4195) ◽  
pp. 1304-1305 ◽  
Author(s):  
P. K. Hansma ◽  
M. Parikh
Keyword(s):  
Electron Irradiation ◽  
Tunneling Spectroscopy ◽  
Spectroscopy Study

scholarly journals Positron Spectroscopy Study of Structural Defects and Electronic Properties of Carbon Nanotubes

2020 ◽  
Vol 20 (2) ◽  
pp. 153-179
Author(s):  
E. A. Tsapko ◽  
I. Ye. Galstian
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Properties ◽  
Structural Defects ◽  
Spectroscopy Study ◽  
Positron Spectroscopy

scholarly journals A deep level transient spectroscopy study of electron irradiation induced deep levels in p-type 6H–SiC

1999 ◽  
Vol 85 (10) ◽  
pp. 7120-7122 ◽  
Author(s):  
M. Gong ◽  
S. Fung ◽  
C. D. Beling ◽  
Zhipu You
Keyword(s):  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Spectroscopy Study ◽  
Transient Spectroscopy ◽  
P Type

Evaluation of single-electron movies of glutamine synthetase molecules

1983 ◽  
Vol 41 ◽  
pp. 280-281
Author(s):  
W. Kunath ◽  
E. Zeitler ◽  
M. Kessel
Keyword(s):  
Electron Microscope ◽  
Glutamine Synthetase ◽  
Electron Irradiation ◽  
Structural Damage ◽  
Structural Changes ◽  
Single Electron ◽  
Continuous Series ◽  
Digital Recording ◽  
Recording Device ◽  
Low Exposure

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.

Radiation-Induced Precipitation at Thin Foil Surfaces in Ni-Be Alloys

1982 ◽  
Vol 40 ◽  
pp. 598-599
Author(s):  
T. Mukai ◽  
T. E. Mitchell
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Electron Irradiation ◽  
High Vacuum ◽  
Thin Foil ◽  
Homogeneous Precipitation ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Radiation Induced

Radiation-induced homogeneous precipitation in Ni-Be alloys was recently observed by high voltage electron microscopy. A coupling of interstitial flux with solute Be atoms is responsible for the precipitation. The present investigation further shows that precipitation is also induced at thin foil surfaces by electron irradiation under a high vacuum.

Void-Lattice Formation in Natural Fluorite by Electron Irradiation

1976 ◽  
Vol 34 ◽  
pp. 614-615 ◽  
Author(s):  
L.E. Murr
Keyword(s):  
Electron Microscope ◽  
Electron Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Stoichiometric Ratio ◽  
Direct Observations ◽  
Transmission Electron ◽  
Anion Vacancies ◽  
Cation And Anion Vacancies ◽  
Lattice Formation

The production of void lattices in metals as a result of displacement damage associated with high energy and heavy ion bombardment is now well documented. More recently, Murr has shown that a void lattice can be developed in natural (colored) fluorites observed in the transmission electron microscope. These were the first observations of a void lattice in an irradiated nonmetal, and the first, direct observations of color-center aggregates. Clinard, et al. have also recently observed a void lattice (described as a high density of aligned "pores") in neutron irradiated Al2O3 and Y2O3. In this latter work, itwas pointed out that in order that a cavity be formed,a near-stoichiometric ratio of cation and anion vacancies must aggregate. It was reasoned that two other alternatives to explain the pores were cation metal colloids and highpressure anion gas bubbles.Evans has proposed that void lattices result from the presence of a pre-existing impurity lattice, and predicted that the formation of a void lattice should restrict swelling in irradiated materials because it represents a state of saturation.

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

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