Unirradiated Films Research Articles

Effect of gamma irradiation on the linear and non-linear optical properties of magnetron Co-sputtered CdO–SnO2 thin films

In this work, CdO–SnO2 thin films were deposited using the magnetron Co-sputtering technique. The presence of single-phase Cadmium Stannate (Cd2SnO4) films was verified by X-ray diffraction (XRD) of the as-prepared and irradiated films. The obtained results reveal that crystallite size (D) increasing by gamma irradiation up to 50 kGY and then seem to be not affected by increasing the dose of gamma radiation for the different phases. The resulting dislocation density (δ) and number of crystallites per unit area (N) decreased irradiation of gamma till 50 kGY and seem to be not affected by increasing gamma irradiation. The microstrain εc did not show systematic variations with gamma dose. The refractive index of un-irradiated and irradiated films showed normal dispersion. Aurbach tail Eu, plasma frequency (ωp), and third order susceptibility χ(3) increased by irradiation and seem to be not affected by increasing gamma dose beyond 50 kGY. In contrast, the optical energy gap Eop found to be decrease by irradiation and seem to be not affected by increasing gamma dose beyond 50 kGY. Other optical parameters, including the absorption coefficient, and dispersion energies, are investigated before and after gamma irradiation.

Tuning critical current density properties of YBa2Cu3O y thin films under longitudinal magnetic field by using heavy-ion irradiation

We attempted to improve the critical current density J c under a longitudinal magnetic field (LMF) by using columnar defects (CDs) tilted toward the transport current, where the CDs were produced with 80 MeV Xe ions at an incident angle(s) up to φ i = 87.5° relative to the c-axis of YBa2Cu3O y thin films. The formation of CDs extending throughout the film was confirmed by cross-sectional transmission electron microscopy. The CDs tilted at φ i = 87.5° weakened the magnetic field dependence of J c under the LMF, providing a J c higher than that of the unirradiated film in a high magnetic field. This is the first study to demonstrate that CDs and/or irradiation defects contribute to flux pinning under the LMF in high-T c superconductors. In addition, the J c under LMF was sensitive to the tilt angle of the CDs: the J c was reduced by CDs tilted not only at φ i = 0°, but also at a slightly larger angle relative to the ab-plane, i.e. φ i = 85°. The introduction of CDs rather disturbs the LMF effect because of the large volume passing through the film thickness, unless the tilt angles of the CDs are within the narrow angular region effective for the LMF effect.

Gafchromic EBT3 film provides equivalent dosimetric performance to EBT-XD film for stereotactic radiosurgery dosimetry

The accurate assessment of film results is highly dependent on the methodology and techniques used to process film. This study aims to compare the performance of EBT3 and EBT-XD film for SRS dosimetry using two different film processing methods. Experiments were performed in a solid water slab and an anthropomorphic head phantom. For each experiment, the net optical density of the film was calculated using two different methods; taking the background (initial) optical density from 1) an unirradiated film from the same film lot as the irradiated film (stock to stock (S-S) method), and 2) a scan of the same piece of film taken prior to irradiation (film to film (F-F) method). EBT3 and EBT-XD performed similarly across the suite of experiments when using the green channel only or with triple channel RGB dosimetry. The dosimetric performance of EBT-XD was improved across all colour channels by using an F-F method, particularly for the blue channel. In contrast, EBT3 performed similarly well regardless of the net optical density method used. Across 21 SRS treatment plans, the average per-pixel agreement between EBT3 and EBT-XD films, normalised to the 20 Gy prescription dose, was within 2% and 4% for the non-target (2—10 Gy) and target (> 10 Gy) regions, respectively, when using the F-F method. At doses relevant to SRS, EBT3 provides comparable dosimetric performance to EBT-XD. In addition, an S-S dosimetry method is suitable for EBT3 while an F-F method should be adopted if using EBT-XD.

Methodical tuning of NH3 gas sensing in WO3 thin films by electron beam irradiation

The present work focuses on the structure, morphology, optical and sensing analysis of Electron Beam Irradiation (EBI) treated WO3 films synthesized by the spray pyrolysis technique. X-ray diffraction (XRD) revealed a slight shift in the 2θ position, indicating stress generated due to EBI process. Scanning Electron Microscopy (SEM) morphographs presented well-defined grains at higher irradiation dosages. X-ray Photoelectron Spectroscopy (XPS) studies showed increased oxygen vacancy defects for the 5 kGy treated sample compared to unirradiated WO3. Sensing analysis of unirradiated and EBI-treated films was conducted towards ammonia (NH3) at an optimum operating temperature of 200 °C. Sensor response of 5 kGy treated film increased by − 4.5 fold compared to unirradiated film at 5 ppm NH3 concentration. The current study demonstrates the importance of EBI in tailoring the NH3 sensing properties of WO3 films.

DOSE MAP BLOOD IRRADIATOR DOSIMETRY SYSTEM: CUSTOMIZED BLOOD EQUIVALENT PHANTOM AND GAFCHROMIC EBT-XD FILM

Blood irradiation is done to sterilize and cease donor T-lymphocytes functionality to avoid Transfusion Associated-Graft Versus Host Disease (TA-GVHD). Dose mapping is the primary means of ensuring that the irradiation process is being conducted correctly. The aim of this study is to measure the minimum, maximum and central absorbed gamma radiation dose delivered at the newly customized blood equivalent phantom using a Gafchromic EBT-XD film. A Gammacell 3000 Elan Blood Irradiator with Cesium-137 source was used. To obtain the dose calibration curves, the films were placed at the center of a phantom and irradiated with the dose range from 5 Gy to 35 Gy with one unirradiated film as a control. The dose calibration curve was plotted using red, green and blue channels. While, for the dose mapping measurement, the irradiation exposure of 9.03 minutes was used to deliver a central dose of 25 Gy to the film. The response of the film will be compared with the GC Dose Mapping Report 2022 which used a water equivalent medium as a phantom. For the calibration curve, the red channel of the film was utilized in this study as it had a higher signal than the other channel. The doses obtained at central, minimum and maximum using EBT-XD film with customized blood equivalent phantom were in agreement with that obtained from GC Dose Mapping Report 2022 to be within ±7.6%, ±8.51% and ±9.95% respectively. We concluded that the customized blood equivalent phantom together with EBT-XD film has a potential to map the dose in blood irradiator accurately. The doses obtained from EBT-XD film were in the range of doses needed to inhibit the proliferation of the T-lymphocytes with central, minimum and maximum doses were 26.9 Gy, 17.2 Gy and 35.7 Gy respectively.

Novel polyvinyl alcohol film dosimeter containing 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide dye for high dose application

A new dyed polyvinyl alcohol (PVA) film dosimeter based on 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MMT) tetrazolium dye is proposed in this study for measuring high gamma radiation dose. Gamma cell irradiator that contains Co-60 gamma-ray source was used to expose the novel MMT-PVA films to different doses up to 25 kGy. The changed in optical property of irradiated and unirradiated films were characterized by UV–Vis spectrophotometer. The results show that the dose sensitive and the linear range of irradiated films were increased considerably with increase of MMT concentration from 1 to 5 mM. The dose response of dyed PVA film changed substantially with changing relative humidity (12–74%) as well as irradiation temperature (10–40 °C). The absorbance of the un-irradiated films does not change up to 10 days in dark while a significant increase in their absorbance was reported for similar films under fluorescent light. The irradiated dosimeters that kept in dark showed a perfect stability for 54 days. It was found that no obvious impact of dose rate on the irradiated MMT-PVA film dosimeters.

Sewage sludge induces changes in the surface chemistry and crystallinity of polylactic acid and polyethylene films

Plastic pollution is a major threat facing our environment. To understand the full effects, we must first characterize how plastics break down in environmental systems. Heretofore, there has been little work examining how exposure to sewage sludge facilitates the degradation of plastics, particularly of plastics that have been previously weathered. Herein, we characterize how the crystallinity, surface chemistry, and morphology of polylactic acid (PLA) and polyethylene (PE) films change due to sludge exposure. In this work, sludge-induced changes in carbonyl index were found to depend on the level of prior exposure to ultraviolet (UV) irradiation. The carbonyl indices of un-irradiated films increased while those of UV-aged films decreased after 35 days of sludge exposure. In addition, the carbon‑oxygen and hydroxyl bond indices of PE films increased with sludge exposure, suggesting the surface oxidation of PE. As for PLA, crystallinity was found to increase with sludge exposure, consistent with a chain scission mechanism. This work will help to predict the behavior of plastic films after transfer from wastewater to sewage sludge.

Shaping Perpendicular Magnetic Anisotropy of Co2MnGa Heusler Alloy Using Ion Irradiation for Magnetic Sensor Applications.

Magnetic sensors are key elements in many industrial, security, military, and biomedical applications. Heusler alloys are promising materials for magnetic sensor applications due to their high spin polarization and tunable magnetic properties. The dynamic field range of magnetic sensors is strongly related to the perpendicular magnetic anisotropy (PMA). By tuning the PMA, it is possible to modify the sensing direction, sensitivity and even the accuracy of the magnetic sensors. Here, we report the tuning of PMA in a Co2MnGa Heusler alloy film via argon (Ar) ion irradiation. MgO/Co2MnGa/Pd films with an initial PMA were irradiated with 30 keV 40Ar+ ions with fluences (ions·cm-2) between 1 × 1013 and 1 × 1015 Ar·cm-2, which corresponds to displacement per atom values between 0.17 and 17, estimated from Monte-Carlo-based simulations. The magneto optical and magnetization results showed that the effective anisotropy energy (Keff) decreased from ~153 kJ·m-3 for the un-irradiated film to ~14 kJ·m-3 for the 1 × 1014 Ar·cm-2 irradiated film. The reduced Keff and PMA are attributed to ion-irradiation-induced interface intermixing that decreased the interfacial anisotropy. These results demonstrate that ion irradiation is a promising technique for shaping the PMA of Co2MnGa Heusler alloy for magnetic sensor applications.

Studies on characterization of blue emissive chitosan/carbazolyl biphenyl (CRB) composite films and their gamma ray irradiation mediated fluorescence quenching phenomenon

Herein, 4,4′-bis(9H-carbazol-9-yl) biphenyl (CRB) a known PhOLED was incorporated into bioplastic chitosan films (CHCRB) resulted in blue emissive composite films with high efficiency. This work presents the interesting change in optical properties of chitosan/CRB composite films wherein an insulator material has been converted into organic semiconductor material. The doping with CRB converted the non-emissive chitosan films as excellent deep blue light emissive materials which is of prime requirement for white LED. Upon irradiation, with gamma ray (15, 25, 45 kGy), the structural and morphological changes occurred in the fabricated films evidenced by analytical, spectroscopic and mechanical studies. The chitosan films exhibited UV absorption at λmax 301 nm (UVB) for unirradiated and broad absorption band at λmax 325 nm (UVA) for irradiated CHCRB films with energy band gap ranging from 2.83 to 2.03eV. Though the unirradiated films showed high intensity deep blue emission at λmax 392 nm with QY of 35.15%, photoluminescence intensity, decreased gradually to QY of 25.26% upon gamma ray irradiation in a dose dependent manner at λmax 392 nm.The quenching of fluorescence could be attributed to the photo induced electron transfer from chitosan to CRB under high energy irradiation. Spectroscopic evidences indicated by the appearance of a new absorption band in FTIR spectra at 1228 cm−1 and a peak at 401.7eV in XPS owing to the formation of quaternary nitrogen on CRB upon electron transfer. Also, colour measurement from CIE diagram indicated the material could also be used as blue emissive material in the devices. Hence, environmentally benign bioplastic films were prepared by simple technique which exhibited both UV absorbing and blue light emissive properties. This work proposes a way to make novel emissive bioplastic films which will be useful for optoelectronic as well as sensing applications.

Influence of swift heavy ion irradiation on bimetallic gold-silver nanoparticles in dielectric matrices and their optical properties

Nanosized gold-silver (AuAg) alloy nanoparticles (NPs) of sizes, 2 nm -25 nm embedded in fused quartz are synthesized using sequential implantation and post annealing at 900℃ for 1 h in Argon environment. The post annealed film is irradiated using swift heavy ions (SHI), 120 MeV Ag ions to investigate the effect of electronic energy deposition, (Se×ϕ), on size, shape and composition of the alloy NPs. Transmission electron microscopy (TEM) analysis of the as- implanted AuAg film reveals the formation of small sized, 1.8 nm-3.5 nm, bimetallic AuAg NPs. Rutherford backscattering spectroscopy (RBS) spectra along with its fitted graph convey the annealing induced out diffusion, mixing and formation of larger sized, 2 nm -25 nm, alloy NPs through Ostwald ripening. SHI irradiation results in deformation in shape from spherical to ellipsoidal alloy NPs with major axis align along the beam direction and the average aspect ratio is about 1.20. RBS analysis results convey the formation of Ag enriched alloy NPs after irradiation. The smaller nanoparticles are found dissolved while larger ones grow and elongate along the ion beam direction. SPR properties are modified by SHI induced processes of melting, sputtering and re-precipitation in the ion tracks.The un-irradiated film exhibits a single intense SPR peak at 536 nm, while the irradiated film gives rise two SPR peaks: Ist, a blue shifted SPR peak from 536 nm to 515 nm with significantly reduced intensity and much wider FWHM; and, IInd, a small SPR peak around 460 nm. SHI induced modifications on the NPs are understood in terms of thermal spike model. The detailed analysis shows that SHI can be used as a tool to tailor size, shape and composition of the bimetallic AuAg alloy NPs and their SPR properties.

A high-sensitive microwave humidity sensor based on one-step laser direct writing of dielectric silver nanoplates

Microwave technology has emerged as an appealing alternative for building humidity sensors with multiple detection parameters. This paper demonstrates the one-step laser direct writing fabrication of microwave humidity sensors. Silver nanoplates were used as both the humidity-sensitive material and a precursor to highly conductive Ag electrodes. Particularly, the unirradiated silver nanoplates film shows an unusual lossy dielectric nature, with the effective complex dielectric permittivity being dramatically tuned by humidity stimuli. Through a laser-induced sintering mechanism, laser irradiation bursts the conductivity by approximately 10 orders of magnitude with a maximum conductivity value of 9.7 × 106 S/m. A prototype microwave humidity sensor is designed and fabricated and its humidity sensing performances are comparatively studied and discussed. The measured results show that the sensor displays a high humidity sensitivity of up to 12.61 MHz/RH or 0.288 dB/RH. This work suggests a good candidate approach for the realization of high-performance microwave humidity sensors with a fast and simplified advantage.

Preferential grain growth, tunable bandgap and topological insulating to bulk state modification induced via Ag ion irradiation in antimony telluride nanostructured thin film

Ion irradiation has been an important technique to alter the physical properties of materials for desired applications. Sb2Te3 thin films deposited via vacuum thermal evaporation procedure are Ag ion irradiated at various fluences. Preferential grain growth along the [104] direction and reduction in optical bandgap from 1.37 eV for unirradiated thin films to 1.14 eV for irradiated thin films is noticed. The value of the Seebeck coefficient decreases with ion fluences 1 × 1010 and 1 × 1012 ions/cm2 owing to the variation in carrier concentration as evident from the Hall measurements. Interestingly, the value of the Seebeck coefficient of the pristine film (457 μV/K at 313 K) is higher than previously reported value in these materials. The study might be catchy to tailor the physical properties of alloys for thermophotovoltaic applications.

Effects of 120 MeV Ag9+ swift heavy ion irradiation on the structural, optical and electrical properties of pristine and Ni doped BiFeO3 thin films grown by pulsed laser deposition

In this work, the effects of swift heavy ion (SHI) irradiation on the structure, morphology, optical and electrical properties of pristine and Ni-doped BiFeO3 thin films have been explored. The thin films with composition of BiFe1-xNixO3 (x = 0, 0.01, 0.03 and 0.05) were deposited on the n-type single crystal Si(100) substrates through pulsed laser deposition technique. Further, irradiation on the thin films was performed with 120 MeV Ag9+ ions at different ion fluences, i.e., 1 × 1013, 5 × 1013 and 1 × 1014 ions/cm2. To investigate the effects of SHI irradiation on the aforementioned properties, all the films have been characterized by various analytical techniques, such as X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, UV-visible diffuse reflectance spectroscopy and two-probe resistivity setup. The effects of the irradiation on the crystal structure and phase of the thin films were analyzed by the XRD and Raman measurements, and it has been observed that irradiation tends to amorphize the thin films. A decrease in the band gap has been observed for the irradiated thin films with the increase of ion fluence. The current-voltage plots of all the unirradiated and irradiated thin films demonstrate the rectifying diode type characteristics.

Understanding the change in electrical resistance of TiO2 thin film irradiated with YVO4 third‐harmonic generation pulse laser

AbstractTo selectively control the electrical resistance, thin films of TiO2 were irradiated with a YVO4 third‐harmonic generation pulse laser in various power conditions. It was observed that when the laser power was less than 0.26 W, the electrical resistance of thin films decreased with the increase in laser power, whereas when the laser power was more than 0.26 W, the electrical resistance increased as the laser power increases. The minimum electrical resistance of the irradiated thin film was found to be four orders of magnitude lower than that of the unirradiated thin film. X‐ray absorption fine structure analysis revealed that the valence of Ti ions in the thin films was reduced after laser irradiation, indicating the formation of oxygen vacancies with electron doping. The cross‐sectional observation by a scanning electron microscope revealed that high laser power irradiation caused the thin films to become porous, and the percolation theory explains the origin of the increase in electrical resistance with developing porous structure. We propose a phase diagram to completely explain the relationship between electrical resistance and laser power, which supply a guideline on laser modification in TiO2 electrical resistance.

Ion-irradiation-induced effects on the surface characteristics of Ge–Bi–Se thin films

In this study, fabricated amorphous chalcogenide Ge10Se70Bi20 thin films were irradiated with nitrogen (N+), argon (Ar+), hydrogen (H+) and oxygen (O+) ion beams. The compositions of the pure and irradiated films were investigated using X-ray diffraction, which confirmed the amorphous structures of the pristine and the irradiated Ge10Se70Bi20 thin films. The optical parameters such as optical bandgap, absorption edge, Urbach energy, Tauc parameter and extinction coefficient of the unirradiated and irradiated films were determined using ultraviolet/visible spectroscopy. The energy gap was found to reduce from 1.355 eV for unirradiated Ge10Se70Bi20 to 1.02, 0.73, 0.60 and 0.51 eV after irradiation with nitrogen, argon, hydrogen and oxygen ion beams, respectively. Meanwhile, the band tail of Ge10Se70Bi20, which is 0.12 eV, increased to 0.16, 0.40, 0.45 and 0.48 eV after irradiation with nitrogen, argon, hydrogen and oxygen ion beams, respectively. In particular, the conductivity increased by two orders after the pristine film had been exposed to an oxygen beam. The direct current electrical conductivity of the pristine film increased from 1.5 × 10−7 to 1.4 × 10−5 Ω−1 cm−1 after irradiation with an oxygen ion beam. Furthermore, the activation energy and Mott’s parameters of the original and irradiated Ge10Se70Bi20 films were deduced. The reported modifications of the optical and electrical parameters suggest the use of irradiated Ge10Se70Bi20 thin films in important applications – for example, optical data storage and optoelectronic devices.

Oxygen irradiation induced modification on the linear and nonlinear optical behavior of flexible MC/PANI/Ag polymeric nanocomposite films

• Irradiated of flexible MC/PANI/Ag nanocomposite films using homemade cold cathode ion source. • Studying the effect of oxygen irradiation on the structural and functional groups of MC/PANI/Ag composite films. • Improving the linear and nonlinear optical behavior of the irradiated MC/PANI/Ag for optoelectronics applications. In the present work, flexible polymeric composite films composed of polyaniline (PANI), silver nanoparticles (AgNPs), and methylcellulose (MC) are synthesized using solution cast preparation method for applied in optoelectronic devices. Subsequently, the MC/PANI/Ag films have been irradiated using broad beam homemade cold cathode ion source with oxygen fluence 8 × 10 17 , 16 × 10 17 , and 24 × 10 17 ions·cm −2 . The synergistic effects of oxygen irradiation on the structure, functional groups and optical properties of MC/PANI/Ag composite films are investigated using X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) and UV–Vis spectroscopy, respectively. The optical band gap and Urbach energy of un-irradiated and irradiated MC/PANI/Ag films were calculated using Tauc's relation. Furthermore, the linear optical parameters such as refractive index, dielectric constant, extinction coefficient, and dielectric loss are determined. Moreover, the Wemple and Di-Domenico model was used to compute the dispersion properties of the studied films. The non-linear optical susceptibility and non-linear refractive index of the un-irradiated and irradiated films were also evaluated. As a consequence, ion-induced structural and optical changes in MC/PANI/Ag composite films, which would clear the way for using irradiated MC/PANI/Ag flexible nanocomposite films for a range of applications, particularly optoelectronic devices.

Effect of zirconium-ion irradiation on properties of secondary phase particles in zirconium-oxide film

To estimate the effect of displacement damage by neutron irradiation of an oxide film of zirconium alloy , a Zircaloy-2 sample was corroded in high temperature and high pressure water at 561 K for 1000 h to form an oxide film. It was then irradiated with 3-MeV Zr 2+ ions up to 1.3 × 10 20 ions/m 2 at 573 K. Subsequently, the crystalline properties of the oxide film and nature of secondary phase particles (SPPs) in the oxide film were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and secondary-ion mass spectrometry (SIMS). From the results off the XRD measurement, monoclinic-ZrO 2 was found to be predominant at operation temperature of a light-water reactor, and slightly tetragonal ZrO 2 was also confirmed. The diffraction peaks of the monoclinic ZrO 2 were slightly clearer in the case of the irradiated sample than in the case of the unirradiated sample. Specifically, ratio of tetragonal ZrO 2 (011) diffraction to monoclinic ZrO 2 (-111) diffraction was increased by irradaiation. In addition, half width of monoclinic ZrO 2 (-111) diffraction was decreased with irradiation dose. This result suggests that the crystallinity of the oxide film was macroscopically improved by the ion irradiation . The diffracted wave corresponding to the (011) plane of the tetragonal ZrO 2 was also revealed after irradiation. It may suggest that tetragonal ZrO 2 is stabilized by accumulation of irradiation defects. However, the crystal structure difference between irradiated and unirradiated is small. Detailed TEM observation of the oxide film confirmed transition from crystalline to amorphous phase in the SPPs near the metal-oxide interface. Furthermore, the diffraction pattern taken from the SPPs near the surface of the oxide film could not be distinguished from that of ZrO 2 . That is, it was concluded that those near the surface of the oxide film were assimilated into ZrO 2 . Their iron concentration was less than that near the metal/oxide interface. Following the TEM observation, SEM observation was performed in the vicinity of the area where the TEM image was obtained. According to the SEM observation, the number of SPPs in the ion-irradiated oxide film tended to be lower than that in the unirradiated oxide film. This tendency was more significant near the surface than near the metal-oxide interface. It is therefore concluded that ZrO 2 in the oxide film is not easily irradiated; however, the SPPs are affected by the irradiation, and dissolution of the alloying elements from the SPPs to the matrix of the oxide film is promoted by substitution irradiation damage.

Structural and electrical properties of irradiated flexible ZnO/PVA nanocomposite films

In this work, the structure and dielectric properties of flexible films composed of zinc oxide nanoparticles (ZnONPs) mixed with polyvinyl alcohol (PVA) polymer are irradiated with different fluence of argon ion beam (8 × 1017, 16 × 1017 and 24 × 1017 ions/cm2). The zinc oxide (ZnO)/PVA composite films were synthesised using the solvent casting preparation method and then characterised using X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The XRD showed that ZnO/PVA composite films were successfully fabricated, and the FTIR peaks indicated that ZnONPs had a chemical interaction with PVA polymer chains. Furthermore, the AC conductivity, dielectric permittivity, electric modulus and energy density efficiency of the un-irradiated and irradiated films were determined using an inductance, capacitance and resistance meter in the frequency range 102–106 Hz. The dielectric constant, ε′, of the composite film increased from 1.38 for un-irradiated ZnO/PVA to 1.88 after being irradiated by 24 × 1017 ions/cm−2, and the conductivity is improved from 7.8 × 10−5 to 10.6 × 10−5 S/cm. The obtained results demonstrated that the dielectric characteristics of the irradiated ZnO/PVA composite films were enhanced; hence, will support these materials in current electronic applications.

Morphological and mechanical evolution of nanostructured ZrN thin films under 165 keV argon ions irradiation

Zirconium nitride is a promising candidate ceramic material to be adopted as an inert matrix for transuranic fuel, a new fuel concept having as targets the closing of the nuclear fuel cycle, and reduce the environmental impact of nuclear waste. Nevertheless, the comprehension of radiation tolerance of zirconium nitride still limited. In this paper, we have studied the radiation stability of nanostructured zirconium nitride (ZrN) thin films using 165 keV argon-ions (Ar2+) irradiation at room temperature. After irradiation, the microstructural, morphological and mechanical properties of the irradiated ZrN films were investigated and compared to an un-irradiated reference film. The grazing incidence X-ray diffraction tests (GI-XRD) revealed a (100) ZrN textured films, the atomic force microscope (AFM) and the scanning electron microscope (SEM) images showed that the as-deposited ZrN films were nano-crystalline with spherical grains of about 50 nm in size and rms surface roughness of about 1.175 nm. After irradiation, the estimate grains size was found to increase to 72 and 86 nm for films irradiated to 2.3 and 22.3 (dpa) respectively, indicating grains coalescence. The nano-hardness of the irradiated films compared to the un-irradiated film was decreased for both doses, while the XRD patterns demonstrate a crystalline ZrN even at the higher dose of 22.3 (dpa), suggesting along with AFM and SEM results grain growth without amorphisation.

Oxygen ion induced variations in the structural and Linear/Nonlinear optical properties of the PVA/PANI/Ag nanocomposite film

In this work, the solution cast method was used to synthesize PVA/PANI/Ag nanocomposite films. Subsequently, the PVA/PANI/Ag films have been irradiated using oxygen ion beam irradiation fluence (8x1017, 16x1017, and 24x1017 ions/cm2). The effect of ion irradiation on the crystal structure and functional groups of PVA/PANI/Ag films was investigated by X-ray diffraction (XRD) and Fourier transforms infrared (FT-IR) respectively. Additionally, the scanning electron microscope (SEM) analysis was used to reveal the change in surface morphology of the irradiated films. The optical band gap and Urbach energy of the unirradiated and irradiated PVA/PANI/Ag films have been determined by employing Tauc’s relation. Furthermore, the linear optical parameters, including extinction coefficient, refractive index, dielectric constant, and loss have been deduced. Besides, the dispersion parameters of the studied films were computed by Wemple and Di-Domenico model. Additionally, non-linear optical susceptibility and non-linear refractive index have been calculated for the unirradiated and irradiated films. The reported results show that the irradiated film by 24x1017 ions/cm2 is considered the best for non-linear optical applications and more convenient to the optoelectronic device.