X-Ray Induced Optical Absorption in Densified Silica Glass in the UV Region

1991 ◽  
Vol 251 ◽  
Author(s):  
Naoyuki Kitamura ◽  
Yutaka Toguchi ◽  
Isao Kondoh ◽  
Hiroshi Yamashita
Keyword(s):  
Optical Absorption ◽  
Point Defects ◽  
Room Temperature ◽  
Hot Isostatic Pressing ◽  
Operating Pressure ◽  
X Rays ◽  
Absorption Bands ◽  
X Ray ◽  
Silica Glasses ◽  
Oh Content

ABSTRACTX-ray induced optical absorption has been studied on silica glasses densified by hot isostatic pressing. Density of the glass increases up to about 1% in proportion to the operating pressure. Two main absorption bands centered at 5.8eV(215nm) and 4.8eV(260nm) are induced both in the densified and undensified glasses under the irradiation of X-rays at room temperature. The 5.8eV band is enhanced with the increase in density for the glass with low-OH content(<˜200ppm), but is decreased slightly for the glass with high-OH content(>˜200ppm). On the other hand, the 4.8eV band decreases with the increase in density irrespective of OH content, and reaches at a constant value above the densification of about 0.5%. It is found that these absorption bands originate in point defects in the glass and that the densification improves the optical durability of the glass against X-rays when hydroxyl impurities are contained in the glass.

scholarly journals Synthesis and Characterisation of Thin Films of Bismuth Triiodide for Semiconductor Radiation Detectors

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Alka Garg ◽  
Monika Tomar ◽  
Vinay Gupta
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Room Temperature ◽  
Active Material ◽  
Visible Region ◽  
Radiation Detectors ◽  
Radiation Absorption ◽  
X Rays ◽  
X Ray ◽  
Bismuth Iodide

Bismuth iodide is a potentially active material for room temperature radiation detector, as it is well reported in the literature that it has both wide energy band gap and high atomic absorption coefficient. Crystalline films of high atomic number and high radiation absorption coefficient can absorb the X-rays and convert them directly into electrical charges which can be read by imaging devices. Therefore, it was proposed to grow thin films of Bismuth iodide on glass substrate using thermal evaporation technique in vacuum to avoid the inclusion of impurities in the films. The structural studies of the films were carried out using XRD and optical absorption measurement was carried out in the UV/VIS region using spectrophotometer. All Bismuth iodide films grown at room temperature are polycrystalline and show X-ray diffraction peaks at angles reported in research papers. The optical transmission spectra of BiI3 films show a high transmission of about 80% in visible region with a sharp fall near the fundamental absorption at 650 nm. Resistivity of the as-grown film was found to be around 1012 ohm-cm suitable value for X-ray detection application. Films were subjected to scanning electron microscopy to study the growth features of both as-grown and annealed films.

Hydrogen Redistribution in Technically Pure Titanium Alloy under X-Ray Exposure at Room Temperature

2014 ◽  
Vol 880 ◽  
pp. 74-79 ◽  
Author(s):  
Viktor N. Kudiiarov ◽  
Andrey M. Lider ◽  
Natalya S. Pushilina
Keyword(s):  
Titanium Alloy ◽  
Surface Area ◽  
Exposure Time ◽  
Room Temperature ◽  
Hydrogen Diffusion ◽  
Pure Titanium ◽  
Hydrogen Desorption ◽  
X Rays ◽  
X Ray ◽  
State Increase

This paper presents experimental results in study of hydrogen redistribution in technically pure titanium alloy under X-ray exposure at room temperature. It is demonstrated that X-ray exposure to titanium with hydrogen affects hydrogen diffusion and redistribution from the surface area to the depth of the samples irrespective of hydrogen condition in titanium: in hydride form or dissolved state. Increase of the exposure time increases the amount of hydrogen redistributed. Hydrogen desorption during irradiation by X-rays at room temperature does not happen.

X-Ray Diffuse Scattering Investigation of Defects in Ion Implanted and Annealed Silicon

1998 ◽  
Vol 524 ◽  
Author(s):  
C. H. Chang ◽  
U. Beck ◽  
T. H. Metzger ◽  
J. R. Patel
Keyword(s):  
Ion Implantation ◽  
Point Defect ◽  
Point Defects ◽  
Diffuse Scattering ◽  
Grazing Incidence ◽  
X Rays ◽  
Scattered Intensity ◽  
X Ray ◽  
Defect Clusters ◽  
Point Defect Clusters

ABSTRACTTo characterize the point defects and point defect clusters introduced by ion implantation and annealing, we have used grazing incidence x-rays to measure the diffuse scattering in the tails of Bragg peaks (Huang Scattering). An analysis of the diffuse scattered intensity will allow us to characterize the nature of point defects or defect clusters introduced by ion implantation. We have also observed unexpected satellite peaks in the diffuse scattered tails. Possible causes for the occurrence of the peaks will be discussed.

The Gas Proportional Scintillation Counter as a Room-Temperature Detector For Energy-Dispersive X-Ray Fluorescence Analysis

1981 ◽  
Vol 25 ◽  
pp. 39-44 ◽  
Author(s):  
C. A. N. Conde ◽  
L. F. Requicha Ferreira ◽  
A. J. de Campos
Keyword(s):  
Room Temperature ◽  
Scintillation Counter ◽  
Fluorescence Analysis ◽  
Energy Dispersive ◽  
X Rays ◽  
Mercuric Iodide ◽  
X Ray ◽  
Temperature Detector ◽  
Portable Instruments ◽  
Physical Principles

AbstractA review of the basic physical principles of the gas proportional scintillation counter is presented. Its performance is discussed and compared with that of other room-temperature detectors in regard to applications to portable instruments for energy-dispersive X-ray fluorescence analysis. It is concluded that the gas proportional scintillation counter is definitely superior to all other room-temperature detectors, except the mercuric iodide (HgI2) detector. For large areas or soft X-rays it is also superior to the HgI2 detector.

The Atomic Order in Guinier-Preston Zones of Aluminum-Silver Alloys

1963 ◽  
Vol 7 ◽  
pp. 1-13 ◽  
Author(s):  
Volkmar Gerold ◽  
Heinz Auer ◽  
Winfried Merz
Keyword(s):  
Room Temperature ◽  
Three Dimensional ◽  
Miscibility Gap ◽  
X Rays ◽  
Atomic Order ◽  
Zone Size ◽  
X Ray ◽  
Angle Scattering ◽  
Diffraction Patterns ◽  
Step Quenching

AbstractThe formation of the spherical Guinier—Preston zones in an aluminum-silver alloy is governed by a metastable miscibility gap, which consists of two different sections. The lower section occurs below 170°C (η state), the higher section up to 420°C (∊ state). The zones in the two sections differ in their silver concentration and in their atomic order. To prove the change in order, a combination of X-ray small-angle scattering and electric resistivity measurements was used. As the resistivity depends on the zone size and the atomic order, the change in order can be found when the zone size is known. This size was measured by the X-ray technique. To complete the results, X-rays ingle-crystal diffraction patterns with monochromatic radiation were taken at different stages. According to these patterns, three different states must be distinguished.The η′ state exists at room temperature after quenching from 550°C. The silver atoms prefer a layered arrangement in the zones, which is not very stable. It is destroyed after short annealings above 100°C. The η state is developed during annealing below 170°C. A three-dimensional atomic order is built up with increasing zone size, which results in a marked decrease in the resistivity. For the ∊ state (above 170°C), a nearly random atomic distribution exists. Step-quenching experiments prove that the ordered η state can also be developed at room temperature.

scholarly journals A Novel X-Ray Radiation Sensor Based on Networked SnO2 Nanowires

2019 ◽  
Vol 9 (22) ◽  
pp. 4878 ◽  
Author(s):  
Jae-Hun Kim ◽  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
Hong Joo Kim ◽  
Phan Quoc Vuong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Low Cost ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Radiation Sensor ◽  
Sno2 Nanowires ◽  
Radiation Sensors

X-Ray radiation sensors that work at room temperature are in demand. In this study, a novel, low-cost real-time X-ray radiation sensor based on SnO2 nanowires (NWs) was designed and tested. Networked SnO2 NWs were produced via the vapor–liquid–solid technique. X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM) analyses were used to explore the crystallinity and morphology of synthesized SnO2 NWs. The fabricated sensor was exposed to X-rays (80 kV, 0.0–2.00 mA) and the leakage current variations were recorded at room temperature. The SnO2 NWs sensor showed a high and relatively linear response with respect to the X-ray intensity. The X-ray sensing results show the potential of networked SnO2 NWs as novel X-ray sensors.

Point Defects in Lithium Fluoride by EUV and Soft X-Rays Exposure for X-Ray Microscopy and Optical Applications

2004 ◽  
Vol 10 (6) ◽  
pp. 1435-1445 ◽  
Author(s):  
G. Baldacchini ◽  
S. Bollanti ◽  
F. Bonfigli ◽  
P. DiLazzaro ◽  
A.Ya. Faenov ◽  
...  
Keyword(s):  
Point Defects ◽  
Lithium Fluoride ◽  
X Rays ◽  
X Ray ◽  
Optical Applications

Ferromagnetism in MgTiO3-Ti2O3 Solid Solutions

2011 ◽  
Vol 700 ◽  
pp. 23-27 ◽  
Author(s):  
Yukari Fujioka ◽  
Johannes Frantti ◽  
Risto M. Nieminen
Keyword(s):  
Room Temperature ◽  
Hexagonal Lattice ◽  
Hysteresis Loops ◽  
Magnetic Impurities ◽  
X Rays ◽  
X Ray ◽  
Cation Layer ◽  
Ferromagnetic Hysteresis ◽  
Secondary Ion ◽  
Ti Content

Ti-rich Mg1ЎxTi1+xO3 samples were synthesized by solid-state reaction. Sampleswere characterized by room temperature x-ray powder di®raction, scanning electron microscopyand energy dispersive spectroscopy of x-rays. Hexagonal lattice parameters a and c increasedwith increasing Ti content. Time-of-Flight-Secondary-Ion-Mass-Spectroscopy (ToF-SIMS, de-tection limit 10Ў6) measurements revealed that no magnetic impurities were present. Sampleswith x = 0:10; 0:12 and 0:32 showed ferromagnetic hysteresis loops. The result demonstratesthat excess Ti at the Mg-O cation layer controls the magnetic properties. This is a technologicaladvantage especially for thin Їlm applications.

Point Defects in GaAs and Other Semiconductors

1992 ◽  
Vol 279 ◽  
Author(s):  
P. Ehrhart ◽  
K. Karsten ◽  
A. Pillukat
Keyword(s):  
Optical Absorption ◽  
Point Defects ◽  
Irradiation Dose ◽  
Ion Irradiation ◽  
Strongly Correlated ◽  
X Ray Diffraction ◽  
Defect Production ◽  
Annealing Stage ◽  
X Ray ◽  
Interstitial Atoms

ABSTRACTIn order to understand the properties of intrinsic point defects and their interactions at high defect concentrations GaAs wafers were irradiated at 4.5 K with 3 MeV electrons up to a dose of 4.1019 e-/cm2. The irradiated samples were investigated by X-ray Diffraction and optical absorption spectrocopy. The defect production increases linearly with irradiation dose and characteristic differences are observed for the two sublattices. The Ga-Frenkel pairs are strongly correlated and are characterized by much larger lattice relaxations (Vrel=2–3 atomic volumes) as compared to the As-Frenkel pairs (Vrel ≈ 1 at.voL). The dominating annealing stage around 300 K is attributed to the mobility of the Ga interstitial atoms whereas the As-interstitial atoms can recombine with their vacancies only around 500 K. These results are compared to those for InP, ZnSe and Ge. Implications for the understanding of the damage after ion irradiation and implantation are discussed.

COMPOSITION AND OPTICAL CHARACTERISTICS OF ELECTROCHEMICALLY-SYNTHESIZED GaAs NANOCRYSTALS

2004 ◽  
Vol 03 (03) ◽  
pp. 281-292 ◽  
Author(s):  
J. NAYAK ◽  
S. VARMA ◽  
D. PARAMANIK ◽  
S. N. SAHU
Keyword(s):  
Room Temperature ◽  
Low Cost ◽  
Energy Shift ◽  
Electrochemical Technique ◽  
X Rays ◽  
Emission Analysis ◽  
X Ray ◽  
The Core ◽  
Infrared Luminescence ◽  
Binding Energy Shift

The synthesis of the GaAs nanoparticles, having sizes 7 nm to 15 nm, by a low cost electrochemical technique has been reported. The absence of any foreign impurity has been confirmed by the Proton-Induced X-rays Emission analysis. Rutherford Backscattering measurement has been performed in order to estimate the thickness of the nanoparticle-generated thin film as a function of the electrolysis current density. The X-ray Photoelectron Spectroscopic study confirms the formation of GaAs and exhibits the binding energy shift of the core shell electrons as an implication of the nanostructure effect. Very weak infrared luminescence due to the radiative recombination of the impurity bound exciton has been detected from yttrium-doped GaAs nanocrystals, even at room temperature.

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