Study of depth-dependent radiation-induced defects using coherent acoustic phonon spectroscopy

2011 ◽  
Vol 1363 ◽  
Author(s):  
A. Steigerwald ◽  
J. Gregory ◽  
K. Varga ◽  
A.B. Hmelo ◽  
X. Liu ◽  
...  
Keyword(s):  
Point Defects ◽  
Acoustic Phonon ◽  
Complex Interaction ◽  
Reflectivity Signal ◽  
Radiation Induced ◽  
Band Tailing ◽  
Induced Changes ◽  
Induced Defects ◽  
Coherent Acoustic Phonon ◽  
Subsurface Investigations

ABSTRACTHere we study the effect of radiation-induced point defect distributions on the optical reflectivity signal in GaAs using coherent acoustic phonon spectroscopy. We demonstrate that the presence of point defects significantly modifies the optical response, allowing estimation of the depth-dependent defect distribution in a nondestructive and noninvasive manner. We show that the observed changes are dependent on defect-induced changes to the electronic structure, namely defect-induced band tailing of the direct 1.43eV band edge. This provides a method for subsurface investigations on the complex interaction between different defects species and optoelectronic structure.

The Annealing of Neutron Irradiation-Induced Defects in Silicon Carbide

1972 ◽  
Vol 30 ◽  
pp. 682-683
Author(s):  
D. Faulkner ◽  
R.C. Styles
Keyword(s):  
Silicon Carbide ◽  
Electron Microscope ◽  
Thermal Diffusivity ◽  
Neutron Fluence ◽  
Nuclear Radiation ◽  
Annealed Material ◽  
Radiation Induced ◽  
Induced Changes ◽  
Induced Defects ◽  
Irradiation Induced Defects

Radiation-induced changes in the macroscopic dimensions, lattice parameters, strength and thermal diffusivity of various types of silicon carbide suggest that different polytypes of this material may behave differently when subjected to a nuclear radiation field. This paper reports the existence of visible defects in post-irradiation annealed material.RFL (Springfields) self-bonded silicon carbide was irradiated in the WR-1 organic-cooled reactor. The specimens were exposed to a fast neutron fluence of 2.2×1020 nvt (E>0.18 MeV) at a temperature of 700°C. Specimens suitable for examination in the electron microscope (3m.m × 1 m.m thick discs) were subsequently annealed for 4 hrs. at temperatures up to 2000°C. The material was ground down from both sides to approximately 0.25 m.m thick and ion thinned for examination in a Hitachi HU-200E electron microscope equipped with a 40° high resolution tilting stage.

scholarly journals Radiation-Induced Defects and Effects in Germanate and Tellurite Glasses

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3846
Author(s):  
Mikko Hongisto ◽  
Alexander Veber ◽  
Yannick Petit ◽  
Thierry Cardinal ◽  
Sylvain Danto ◽  
...  
Keyword(s):  
Structural Modification ◽  
Glass Composition ◽  
Tellurite Glasses ◽  
Mid Infrared ◽  
Practical Applications ◽  
Radiation Induced ◽  
Transmission Window ◽  
Induced Changes ◽  
Induced Defects ◽  
Induced Crystallization

This review focuses on the radiation-induced changes in germanate and tellurite glasses. These glasses have been of great interest due to their remarkable potential for photonics, in terms of extended transmission window in the mid-infrared, ability of rare-earth loading suitable with a laser, and amplification in the near- and mid-infrared or high nonlinear optical properties. Here, we summarize information about possible radiation-induced defects, mechanisms of their formation, and the influence of the glass composition on this process. Special attention is paid to laser-induced structural modification of these glasses, including possible mechanisms of the laser-glass interaction, laser-induced crystallization, and waveguide writing. It is shown that these methods can be used for photostructuring of the glass and have great potential for practical applications.

Radiation Induced Effects on Properties of Semiconducting Nanomaterials

2015 ◽  
Vol 239 ◽  
pp. 1-36 ◽  
Author(s):  
S.K. Tripathi ◽  
Jagdish Kaur ◽  
R. Ridhi ◽  
Kriti Sharma ◽  
Ramneek Kaur
Keyword(s):  
Heavy Ion ◽  
Irradiation Effect ◽  
Defect States ◽  
Γ Irradiation ◽  
Beneficial Effects ◽  
Radiation Induced ◽  
Induced Changes ◽  
Induced Defects ◽  
The Impact ◽  
Irradiation Induced Defects

The irradiation of nanomaterials with energetic particles has significant effects on the properties of target materials. In addition to the well-known detrimental effects of irradiations, they have also some beneficial effects on the properties of nanomaterials. Irradiation effect can change the morphology of the materials in a controlled manner and tailor their mechanical, structural, optical and electrical properties. Irradiation induced modifications in the properties of nanomaterials can be exploited for many useful applications. With the aim of getting better performance of electronic devices, it is necessary to discuss the irradiation induced changes in the nanomaterials. In order to improve the irradiation hardness of electronic components, it is also crucial to have a fundamental understanding of the impact of the irradiation on the defect states and transport properties of the host material. In the present article, we review some recent advances on the irradiation induced effects on the properties of semiconducting nanomaterials. We have reviewed the effect of different types of irradiations which includes γ-irradiation, electron beam irradiation, laser irradiation, swift heavy ion irradiations, thermal induced, and optical induced irradiations, etc. on the various properties of semiconducting nanomaterials. In addition, the irradiation induced defects are also discussed.

Structural, Doped, Radiation Defects and Properties of Non-Stoichiometrical Solids

2005 ◽  
Vol 494 ◽  
pp. 55-60 ◽  
Author(s):  
N. Kulagin
Keyword(s):  
Single Crystals ◽  
Point Defects ◽  
Spectral Properties ◽  
Theoretical Data ◽  
Radiation Defects ◽  
Iron Group ◽  
Radiation Induced ◽  
The Stability ◽  
Α Al2o3 ◽  
Induced Defects

The paper includes experimental and theoretical data on spectral properties of oxide single crystals doped with ions of the iron group elements, as well as on the stability of ions oxidation state under irradiation. Experimental data resulting from the investigation of radiation-induced defects into pure and doped single crystals, such as sapphire (α-Al2O3) and garnets (Y3Al5O12, Gd3Ga2Sc3O12, Gd3Sc2Al3O12), are presented. The main conditions of creation of irradiation-induced color centers and point defects, including theoretical analysis, are considered too.

Xenon ion irradiation of superconducting YBa2Cu3O7 thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 92-93
Author(s):  
H. Watanabe ◽  
B. Kabius ◽  
B. Roas ◽  
K. Urban
Keyword(s):  
Defect Formation ◽  
Ion Irradiation ◽  
High Resolution Electron Microscopy ◽  
Structural Disorder ◽  
Flux Lines ◽  
Pinning Effect ◽  
Magnetic Flux Lines ◽  
Resolution Electron ◽  
Radiation Induced ◽  
Induced Defects

Recently it was reported that the critical current density(Jc) of YBa2Cu2O7, in the presence of magnetic field, is enhanced by ion irradiation. The enhancement is thought to be due to the pinning of the magnetic flux lines by radiation-induced defects or by structural disorder. The aim of the present study was to understand the fundamental mechanisms of the defect formation in association with the pinning effect in YBa2Cu3O7 by means of high-resolution electron microscopy(HRTEM).The YBa2Cu3O7 specimens were prepared by laser ablation in an insitu process. During deposition, a substrate temperature and oxygen atmosphere were kept at about 1073 K and 0.4 mbar, respectively. In this way high quality epitaxially films can be obtained with the caxis parallel to the <100 > SrTiO3 substrate normal. The specimens were irradiated at a temperature of 77 K with 173 MeV Xe ions up to a dose of 3.0 × 1016 m−2.

EXAFS STUDY ON RADIATION INDUCED DEFECTS

1986 ◽  
Vol 47 (C8) ◽  
pp. C8-1045-C8-1048
Author(s):  
T. BOLZE ◽  
J. PEISL
Keyword(s):  
Radiation Induced ◽  
Exafs Study ◽  
Induced Defects

scholarly journals Space Radiation-Induced Alterations in the Hippocampal Ubiquitin-Proteome System

2021 ◽  
Vol 22 (14) ◽  
pp. 7713
Author(s):  
Alyssa Tidmore ◽  
Sucharita M. Dutta ◽  
Arriyam S. Fesshaye ◽  
William K. Russell ◽  
Vania D. Duncan ◽  
...  
Keyword(s):  
Spatial Memory ◽  
Memory Performance ◽  
Space Radiation ◽  
Label Free ◽  
Proteomic Profiling ◽  
Neurocognitive Deficits ◽  
Male Wistar Rats ◽  
Radiation Induced ◽  
Induced Changes

Exposure of rodents to <20 cGy Space Radiation (SR) impairs performance in several hippocampus-dependent cognitive tasks, including spatial memory. However, there is considerable inter-individual susceptibility to develop SR-induced spatial memory impairment. In this study, a robust label-free mass spectrometry (MS)-based unbiased proteomic profiling approach was used to characterize the composition of the hippocampal proteome in adult male Wistar rats exposed to 15 cGy of 1 GeV/n 48Ti and their sham counterparts. Unique protein signatures were identified in the hippocampal proteome of: (1) sham rats, (2) Ti-exposed rats, (3) Ti-exposed rats that had sham-like spatial memory performance, and (4) Ti-exposed rats that impaired spatial memory performance. Approximately 14% (159) of the proteins detected in hippocampal proteome of sham rats were not detected in the Ti-exposed rats. We explored the possibility that the loss of the Sham-only proteins may arise as a result of SR-induced changes in protein homeostasis. SR-exposure was associated with a switch towards increased pro-ubiquitination proteins from that seen in Sham. These data suggest that the role of the ubiquitin-proteome system as a determinant of SR-induced neurocognitive deficits needs to be more thoroughly investigated.

scholarly journals Impact of [18F]FDG-PET and [18F]FLT-PET-Parameters in Patients with Suspected Relapse of Irradiated Lung Cancer

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 279
Author(s):  
Tine N. Christensen ◽  
Seppo W. Langer ◽  
Gitte Persson ◽  
Klaus Richter Larsen ◽  
Annemarie G. Amtoft ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Overall Survival ◽  
Fdg Pet ◽  
Tumor Volume ◽  
High Dose ◽  
Flt Pet ◽  
Pet Ct ◽  
Radiation Induced ◽  
Fdg Pet Ct ◽  
Induced Changes

Radiation-induced changes may cause a non-malignant high 2-deoxy-2-[18F]fluoro-d-glucose (FDG)-uptake. The 3′-deoxy-3′-[18F]fluorothymidine (FLT)-PET/CT performs better in the differential diagnosis of inflammatory changes and lung lesions with a higher specificity than FDG-PET/CT. We investigated the association between post-radiotherapy FDG-PET-parameters, FLT-PET-parameters, and outcome. Sixty-one patients suspected for having a relapse after definitive radiotherapy for lung cancer were included. All the patients had FDG-PET/CT and FLT-PET/CT. FDG-PET- and FLT-PET-parameters were collected from within the irradiated high-dose volume (HDV) and from recurrent pulmonary lesions. For associations between PET-parameters and relapse status, respectively, the overall survival was analyzed. Thirty patients had a relapse, of these, 16 patients had a relapse within the HDV. FDG-SUVmax and FLT-SUVmax were higher in relapsed HDVs compared with non-relapsed HDVs (median FDG-SUVmax: 12.8 vs. 4.2; p < 0.001; median FLT-SUVmax 3.9 vs. 2.2; p < 0.001). A relapse within HDV had higher FDG-SUVpeak (median FDG-SUVpeak: 7.1 vs. 3.5; p = 0.014) and was larger (median metabolic tumor volume (MTV50%): 2.5 vs. 0.7; 0.014) than the relapsed lesions outside of HDV. The proliferative tumor volume (PTV50%) was prognostic for the overall survival (hazard ratio: 1.07 pr cm3 [1.01–1.13]; p = 0.014) in the univariate analysis, but not in the multivariate analysis. FDG-SUVmax and FLT-SUVmax may be helpful tools for differentiating the relapse from radiation-induced changes, however, they should not be used definitively for relapse detection.

Annealing of radiation-induced defects in ion-implanted AIIBVI single crystals

1989 ◽  
Vol 32 (3) ◽  
pp. 198-203
Author(s):  
A. N. Georgobiani ◽  
M. B. Kotlyarevskii ◽  
B. P. Dement'ev ◽  
V. N. Mikhalenko ◽  
N. V. Serdyuk ◽  
...  
Keyword(s):  
Single Crystals ◽  
Radiation Induced ◽  
Induced Defects ◽  
Ion Implanted

Formation of Drawing- or Radiation-Induced Defects in Germanium-Doped Silica Core Optical Fiber

1994 ◽  
Vol 33 (Part 2, No. 2B) ◽  
pp. L233-L234 ◽  
Author(s):  
Yoshinori Hayashi ◽  
Yuki Okuda ◽  
Hisamitsu Mitera ◽  
Keizo Kato
Keyword(s):  
Optical Fiber ◽  
Radiation Induced ◽  
Silica Core ◽  
Induced Defects
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