Influence Of X-ray Irradiation Research Articles

Influence of X-Ray Irradiation During Photoemission Studies on Halide Perovskite-Based Devices.

Metal halide perovskites (MHPs) are semiconductorswithpromising application in optoelectronic devices, particularly, in solar cell technologies. The chemical and electronic properties ofMHPs at thesurface and interfaces with adjacent layersdictatecharge transfer within stacked devicesand ultimately the efficiency of the latter. X-ray photoelectron spectroscopy is a powerful tool to characterizethese material properties. However, the X-ray radiation itself can potentially affect the MHP and thereforejeopardize the reliability of the obtained information. In this work, the effect of X-ray irradiation is assessed on Cs0.05 MA0.15 FA0.8 Pb(I0.85 Br0.15 )3 (MA forCH3 NH3 , and FA forCH2 (NH2 )2 ) MHP thin-film samples in a half-cell device. There is a comparison of measurements acquiredwith synchrotron radiation and a conventional laboratory source for different times. Changes in composition and core levels binding energies are observed in both cases, indicating a modification of the chemical and electronic properties. The results suggest that changes observed over minutes with highly brilliant synchrotron radiation are likely occurring over hours when working with a lab-based source providing a lower photon flux. The possible degradation pathways are discussed, supported by steady-state photoluminescence analysis. The work stresses the importance of beam effect assessment at the beginning of XPS experiments of MHP samples.

Ion distribution in iron oxide, zinc and manganese ferrite nanoparticles studied by XPS combined with argon gas cluster ion beam sputtering

In this work, the influence of X-ray irradiation and two types of surface sputtering methods is thoroughly studied. The first one, monoatomic sputtering, resulted in the reduction of iron oxide to the metallic iron in a short time of sputtering. The second studied technique is argon cluster sputtering, which uses lower energies per atom, hence the modification of the structure of the samples is greatly reduced. Based on the XPS characterization of Fe3O4 single crystal the fitting procedure for the Fe 2p spectra for nanoparticles is established. The preliminary results showed that X-rays combined with cluster sputtering resulted in alteration of the morphology and solidification of the surface of the samples. In the response to the morphology modification, the Spot-by-Spot Cluster Procedure is proposed. It allows to thoroughly characterize the layer-by-layer structure of the nanoparticles, without changing it. The Procedure was used to determine the structure of zinc, manganese and zinc-manganese ferrite nanoparticles. Finally, the results show, that depending on the used dopant, its incorporation and the state of iron are changed.

Charge trapping processes in hydrothermally grown Er-doped ZnO

Influence of X-ray irradiation on luminescence properties and defects creation was studied in the erbium doped hydrothermally grown ZnO by using the combination of photo- and radioluminescence (PL and RL), thermally stimulated luminescence (TSL) and electron paramagnetic resonance (EPR). The photoluminescence properties of the ZnO:Er appeared affected by the X-ray irradiation – the intensity of the zinc vacancy-related red band and exciton-related ultraviolet band were weakened. The irradiation also evoked charge trapping and new centers creation whose type and number depended on Er doping. The X-ray induced defects were oxygen-based hole and electron trapping centers, O− and O2−, respectively. The X-ray irradiation had also influence on shallow donors in the bulk and at the surface of the ZnO nano- and microrods. TSL glow curves consisted of one broad peak with the maximum at about 110 K, its intensity was varying with the changing Er content. The glow peak was correlated with the thermal destruction of the unstable O2− electron trapping centers. Zinc vacancies-based defects participated in the thermally stimulated luminescence as recombination centers for the electrons released from the O2−.

Screening of X-ray responsive substances for the next generation of radiosensitizers

X-ray responsivity resulting in the generation of reactive oxygen species (ROS) was investigated in 9600 organic compounds that were selected by considering their structural diversity. We focused on superoxides that were primarily detected using dihydroethidium (DHE) and hydroxyl radicals, that were identified fluorometrically using 3’-(p-aminophenyl) Fluorescein (APF). Many organic compounds were discovered that responded to the DHE and/or APF assay using X-ray irradiation. These results suggest that some of these organic compounds emit either superoxides or hydroxyl radicals whereas others emit both under the influence of X-ray irradiation. The response of the derivatives of a hit compound with a partial change in the structure was also investigated. The products produced from DHE by X-ray irradiation were identified by HPLC to confirm the integrity of the process. Although, the reactions were suppressed by the superoxide dismutase (SOD), not only 2-hydroxyethidium (2-OH-E+), but also ethidium (E+) were detected. The results suggest that apart from a direct reaction, an indirect reaction may occur between DHE and the superoxides. Although X-ray responsiveness could not be inferred due to the molecular complexity of the investigated compounds, delineation of these reactions will facilitate the development of the next generation of radiosensitizers.

Poly(vinyl alcohol) and liposomes as a synthetic biodegradable model membrane for probing radiation interactions

This work aims to investigate the effect of X-rays on poly(vinyl alcohol) (PVA) films and studying the ability to be a model of a synthetic cell membrane when compared to liposomes as biological models. The influence of X-ray irradiation on thin films of PVA doped with safranin (SAF) dye and liposomes encapsulated by SAF dye is studied using UV–visible spectrophotometry. These films are exposed to X-ray radiation with accumulated doses range of 10–50 Gy of 140 kVp at a constant dose rate of 2002 μGy/s. The absorption spectra of the PVA/SAF and the liposomes/SAF are measured. The absorption spectra of the PVA/SAF showed a decrease in the absorbance band peak with the increase of the dose with values are similar to those observed with the liposomes/SAF. The dose response function indicates the same radiation sensitivity of both samples. The results indicated that full width at half maximum of SAF/PVA and SAF/liposomes show linear decrease with an increase of dose. The variation in dose response is relatively small and found to be within 3.5% and the variations in a decrease of the absorbance peak are found to be with maximum 5%. These values can indicate that both of SAF/PVA and SAF/liposomes have the same behavior under the applied X-ray dose range. The results viewed that the PVA doped with SAF dye behave similarly as the liposomes doped with SAF dye. PVA may be used as a synthetic model for a cell membrane for probing X-ray-membrane interactions.

Influence of X-ray irradiation on the optical absorption edge and refractive index dispersion in Cu6PS5I-based thin films deposited using magnetron sputtering

Influence of X-ray irradiation on the optical absorption edge and refractive index dispersion in Cu6PS5I-based thin films deposited using magnetron sputtering

Optical properties of X-ray irradiated Cu<sub>6</sub>PS<sub>5</sub>I-based thin films deposited by magnetron sputtering

Introduction . Cu 6 PS 5 I crystals belong to a big family of compounds with argyrodite structure. They are characterized by high ionic conductivity. That’s why these materials are promising for creation of different type of modern devices such as batteries, supercapacitors, electrochemical sensors, etc. Studies of the influence of external factors on physical properties of Cu 6 PS 5 I materials are important to predict endurance, wear resistance and safety of devices made on their basis. Purpose . The purpose of the paper is to investigate the influence of X-ray irradiation on the optical properties of Cu 6 PS 5 I-based thin films as well as to perform the quantative and qualitative evaluation of the changes that have taken place in the structure “film-substrate” as a result of X-ray irradiation. Methods . Cu 6 PS 5 I-based thin films were deposited onto silicate glass substrates by non-reactive radio frequency magnetron sputtering. The film chemical composition was investigated by energy-dispersive X-ray spectroscopy. X-ray irradiation was performed at different exposition times (30, 60 and 120 min) using wideband radiation of Cu-anode X-ray tube with approx 400 W of power applied (33 kV, 13 mA). Optical transmission spectra of Cu 6 PS 5 I-based thin films were studied using MDR-3 grating monochromator. Results . Optical transmission spectra of X-ray irradiated Cu 5.6 P 1.7 S 4.9 I 0.8 , Cu 6.4 P 1.1 S 4.6 I 0.9 and Cu 8.0 P 0.7 S 3.6 I 0.7 thin films were studied at various irradiation times at room temperature. With irradiation time increase the red shift of the short-wavelength part of transmission spectra and interference maxima is revealed. In the X-ray irradiated thin films the Uhrbach behavior of the optical absorption edge is observed. Optical absorption edge for X-ray irradiated thin films is shifted to the long-wavelength region with irradiation time increase. It leads to the energy pseudogap decrease and Uhrbach energy increase. Dispersion dependences of the refractive index for the X-ray irradiated thin films have shown a slight dispersion of the refractive indices in the transparency region, increasing with approaching the optical absorption edge. With irradiation time increase the nonlinear increase of the refractive indices in the X-ray irradiated thin films is revealed. Conclusions. The influence of X-ray irradiation on optical properties of Cu 6 PS 5 I-based thin films was studied. Changes in optical parameters of the thin films were investigated and described. With irradiation time increase the decrease of energy pseudogap as well as increase of Uhrbach energy and refractive index values was observed. It was determined that with irradiation time increase the darkening and densitification of the thin films occur. The increase of Uhrbach energy indicates on increase of structural disordering induced by the influence of X-ray irradiation.

Photoluminescence excitation of lithium fluoride films by surface plasmon resonance in Kretschmann configuration

We report on excitation of the photoluminescence of lithium fluoride by means of the surface plasmon resonance of Al layer. Advantage of this method is high efficiency of the excitation, which is applicable to ultra-thin films. P-polarized UV diode laser light is coupled to the surface plasmon resonance using a fused silica prism in Kretschmann configuration. The angular dependence of the reflected intensity is measured using a theta–2theta goniometer. The surface plasmon at resonance condition induces photoluminescence in the adjacent lithium fluoride layer. The fluoride layers were deposited on Al-coated fused silica substrates by electron beam evaporation. For the experiment, we prepared several samples with thickness ranging from 20 to 71 nm. We studied the effect of the luminescence enhancement by the surface plasmon resonance effect. Strong quenching effect was observed in the thinnest LiF layer. Influence of X-ray irradiation on the photoluminescence was studied.

Analog performance of standard and uniaxial strained triple-gate SOI FinFETs under x-ray radiation

The influence of x-ray irradiation on the main digital and analog parameters of triple gate silicon-on-insulator FinFETs is investigated for unstrained and uniaxially strained devices. Comparing the p- and n-MuGFET response to radiation, x-rays can be more harmful for nMuGFETs than for the p-type counterparts due to the back-interface leakage current, which is generated by the positive charges trapped in the buried oxide. However, in pMuGFETs, the radiation tends to suppress the parasitic back-conduction, resulting in an improvement of the device performance.

Influence of X-ray irradiation on the properties of the Hamamatsu silicon photomultiplier S10362-11-050C

We have investigated the effects of X-ray irradiation to doses of 0, 200Gy, 20kGy, 2MGy, and 20MGy on the Hamamatsu silicon-photomultiplier (SiPM) S10362-11-050C. The SiPMs were irradiated without applied bias voltage. From current–voltage, capacitance/conductance–voltage, capacitance/conductance–frequency, pulse-shape, and pulse-area measurements, the SiPM characteristics below and above breakdown voltage were determined. Significant changes of some SiPM parameters are observed. Up to a dose of 20kGy the performance of the SiPMs is hardly affected by X-ray radiation damage. For doses of 2 and 20MGy the SiPMs operate with hardly any change in gain, but with a significant increase in dark-count rate and cross-talk probability.

Bimodality of wind-fed accretion in high-mass X-ray binaries

Abstract We here consider the influence of X-ray photoionization from an accreting neutron star in a high-mass X-ray binary. Our aim is to unveil a new principle governing the X-ray luminosity of X-ray binaries, through a simple analysis of fluid equations simulating line-driven wind flow under the influence of X-ray irradiation. In this study, we solved the equation of motion of the accretion flow while taking into account the line-driven acceleration and X-ray photoionization. Under the influence of X-ray irradiation, we have found that the flow equations have two types of solutions. The first is characterized by a slow wind velocity, which causes a large accretion rate. The second solution is a fast wind flow, which results in a small accretion rate. We find that only the solution with a fast wind and faint X-ray luminosity is a steady solution. On the other hand, a slow wind solution with a large X-ray luminosity is not a realizable solution. In bright X-ray binary systems, the X-ray luminosity would increase until strong X-rays reduce the line-driven acceleration, and cause a stagnation of the wind. This implies an important consequence; that is, the X-ray luminosity of the wind-fed, X-ray emitting binary is settled by the limit of wind stagnation. At the same time, the fast-wind solution with a small X-ray luminosity can also represent a steady state. Bright X-ray sources, such as Vela X-1, would have limiting luminosities of wind stagnation, while faint systems, such as quiescent supergiant fast X-ray transients, could follow the faint solution.

Influence of X-ray irradiation on the optical properties of CoMTPP thin films

Thin films of 5,10,15,20-Tetrakis (4-methoxyphenyl)-21 H,23 H-porphine cobalt (II), CoMTPP were prepared at room temperature (300K) by the thermal evaporation technique under vacuum pressure about 2 × 10 − 4 Pa. The X-ray diffraction patterns showed the amorphous nature for the as-deposited and the irradiated films, whereas the powder has shown a polycrystalline with triclinic structure. Miller's indices, hkl, values for each diffraction peak in the XRD spectrum were calculated. Optical properties of CoMTPP thin films were characterized by using spectrophotometric measurements of transmittance and reflectance in the spectral range from 200 to 2500 nm. The refractive index, n, and the absorption index, k, were calculated. The obtained data were used to estimate the type of transitions and the optical and fundamental gaps before and after X-ray irradiation. In addition, the normal dispersion of the refractive index is discussed in terms of lorentz-lorentz free single oscillator model and modified lorentz Drude model of free carrier contribution.

Spectroscopic studies of the origin of radiation-induced degradation in phosphorus-doped optical fibers and preforms

In this paper, we study the radiation-induced point defects related to the phosphorus element that is commonly used to improve the optical properties of silica-based glasses but is responsible of a dramatic increase in their radiation sensitivity. To this aim, the influence of x-ray irradiation on prototype phosphorus-doped canonical fibers and their related preforms was investigated by in situ radiation induced attenuation (RIA), optical absorption, and electron spin resonance (ESR) spectroscopy. The RIA spectra in the (1.5–5 eV) range, can be explained by the presence of at least three absorption bands induced by radiation exposure. Additionally the X-dose dependence of such bands was studied. The main responsible defect for these absorption peaks was the phosphorus oxygen hole center (POHC) center, whose presence was also detected by ESR measurements both in irradiated fibers and preforms, together with the lineshape of the so called P2 defect. Correlations between the RIA bands and the ESR results allow us to assign the 2.3 and 3.0 eV bands to POHCs and to propose a scheme for the simultaneous creation of POHC and P2 defects after x-ray exposure.

Formation of nickel coatings by electrochemical deposition under X-ray irradiation

The influence of X-ray irradiation on the formation of nickel electroplating coatings is studied. The regularities of the nickel electrocrystallization kinetics under X-ray irradiation of different wavelengths, such as the increase in the deposition rate and metal output by the current, are revealed. The features of the structuring of the nickel electroplating coatings under irradiation are revealed. The influence of X-ray irradiation on microhardness, microdeformations, and dislocation structure is estimated. An increase in microhardness and a decrease in microdeformations of nickel coatings with the growth of the radiation energy are established.

Influence of X-ray irradiation on the optical properties of iron (III) chloride tetraphenylporphyrin thin films

The influence of X-ray irradiation in air of iron (III) chloride tetraphenylphorphyrin (FeTPPCl) thin films was carried out in order to investigate changes in optical properties. The changes of refractive index, n, and extinction coefficient, k, were calculated using spectrophotometric measurements of transmittance and reflectance at normal incidence over the spectral range 200–2500 nm. The obtained data of n and k were used to estimate the type of transitions and the optical and fundamental gaps before and after X-ray irradiation. In addition, the normal dispersion of the refractive index is discussed in terms the single oscillator model and Drude model of free carrier absorption.

Control of the properties of Pb(TixZr1-x )O3 solid solutions by external disturbances

The influence of x-ray irradiation to absorbed radiation doses D = (0.5−12) × 108 rad on the properties of ferroelectric ceramic Pb(TixZr1−x)O3 solid solutions with compositions close to the morphotropic phase boundary was studied. The effects of x-ray radiation on the electrical conductivity of ferroelectric ceramics are shown to differ with x ranging from 0.42 to 0.60. Using empirical equations and numerical techniques, quantitative relations are established between the composition, absorbed radiation dose, and electrical conductivity for Pb(TixZr1−x)O3.

Influence of x-ray irradiation on doped europium in BaMgAl[sub 10]O[sub 17] studied by x-ray absorption fine structure and x-ray diffraction

Journal of the Society for Information DisplayVolume 8, Issue 1 p. 1-1 Introduction Andras I. Lakatos, Andras I. Lakatos EditorSearch for more papers by this author Andras I. Lakatos, Andras I. Lakatos EditorSearch for more papers by this author First published: 18 June 2012 https://doi.org/10.1889/1.1828693Citations: 11AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume8, Issue1March 2000Pages 1-1 RelatedInformation

Thickening of a smectic membrane in an evanescent X-ray beam.

We report an unusual thickening of smectic membranes under the influence of X-ray irradiation below the critical angle. In the case of a four-layer film the thickness was found to grow at the footprint of the beam, reaching within minutes tens of layers. The effect is attributed to the localized energy dissipation of the evanescent wave. The "island" thus created is not connected to the meniscus and after the beam is switched off the film returns to its original state. A possible explanation is given in terms of a local disrupture of the tension of the smectic membrane.

Influence of X-ray Irradiation on the Mandible of Ovariectomized Rats

Influence of X-ray Irradiation on the Mandible of Ovariectomized Rats

Influence of X-ray irradiation on the optical properties of chromium-doped KliSO4 crystals

The absorption and circular-dichroism spectra of chromium-activated KLiSO4 crystals both nonirradiated and irradiated with an X-ray beam have been studied. It was established that in nonirradiated crystals chromium ions are mainly trivalent (Cr3+) and have octahedral coordination. In irradiated crystals, along with the centers provided by (Cr3+) ions, new centers are formed associated with (Cr4+) and (Cr5+) ions.