Journal of Radioanalytical and Nuclear Chemistry - Zirconolite, a potential candidate for the immobilization of actinides was investigated for the induced effects of α-particles simulated... 相似文献
High-energy ion beam irradiation of the polymers is a good technique to modify the properties such as electrical conductivity,
structural behaviour and mechanial properties. Polyaniline thin films doped with hydrochloric acid (HCl) were prepared by
oxidation of ammonium persulphate. The effect of Swift Heavy Ions irradiation on the electrical and structural properties
of polyaniline has been measured in this study. Polyaniline films were irradiated by oxygen ions (energy 80 MeV, charge state
O+7) with fluence varying from 1 × 1010 to 3 × 1012 ions/cm2. The studies on electrical and structural properties of the irradiated polymers were investigated by measuring V-I using
four probe set-up and X-ray diffraction (XRD) using Bruker AXS, X-ray powder diffractometer. V-I measurements shows an increase
in the conductivity of the film, XRD pattern of the polymer shows that the crystallinity improved after the irradiation with
Swift Heavy Ions (SHI), which could be attributed to cross linking mechanism.
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Titanium substrate was coated with hydroxyapatite by radiofrequency magnetron sputtering (rf-magnetron sputtering) technique and subjected to swift heavy ion (SHI) irradiation of 125 MeV with Si9+ at fluences of 1 × 1010, 1 × 1011 and 1 × 1012 ions/cm2. The glancing incidence X-ray diffraction (GIXRD) analysis confirmed the HAp phase of the irradiated film. There was a considerable decrease in crystallinity and particle size after irradiation. In addition, DRS-UV reflectance spectra revealed a decrease in optical band gap (Eg) from 5.2 to 4.6 eV. Wettability of biocompatible materials plays an important role in biological cells proliferation for tissue engineering, drug delivery, gene transfer and bone growth. HAp thin films irradiated with 1 × 1011 ions/cm2 fluence showed significant increase in wettability. While the SHI irradiated samples exhibited enhanced bioactivity, there was no significant variation in cell viability. Surface roughness, pores and average particle size were analyzed by atomic force microscopy (AFM). 相似文献
Ge nanocrystals embedded in an SiO2 matrix were prepared by the atom beam co-sputtering (ABS) method from a composite target of Ge and SiO2. The as-deposited films were rapid thermally annealed at the temperatures 700 and 800 °C in nitrogen ambience. The structure of the films was evaluated by using X-ray diffraction (XRD) and Raman spectroscopy. XRD results reveal that as-deposited films are amorphous in nature whereas annealed samples show crystalline nature. Raman scattering spectra showed a peak of Ge–Ge vibrational mode shifted downwards to 297 cm?1, presumably caused by quantum confinement of phonons in the Ge nanocrystals. Rutherford backscattering spectrometry has been used to measure the thickness and Ge composition of the composite films. Size variation of Ge nanocrystals with annealing temperature has been discussed. The advantages of ABS over other methods are highlighted. 相似文献
We report the preparation of multiferroic BiFeO3 thin films on ITO coated glass substrates through sol-gel spin coating method followed by thermal annealing and their modification
by swift heavy ion (SHI) irradiation. X-ray diffraction and Raman spectroscopy studies revealed amorphous nature of the as
deposited films. Rhombohedral crystalline phase of BiFeO3 evolved on annealing the films at 550°C. Both XRD and Raman studies indicated that SHI irradiation by 200 MeV Au ions result
in fragmentation of particles and progressive amorphization with increasing irradiation fluence. The average crystallite size
estimated from the XRD line width decreased from 38 nm in pristine sample annealed at 550°C to 29 nm on irradiating these
films by 200 MeV Au ions at 1 × 1011 ions cm−2. Complete amorphization of the rhombohedral BiFeO3 phase occurs at a fluence of 1 × 1012 ions.cm−2. Irradiation by another ion (200 MeV Ag) had the similar effect. For both the ions, the electronic energy loss exceeds the
threshold electronic energy loss for creation of amorphized latent tracks in BiFeO3. 相似文献
Accurate measurement of natural and anthropogenic radionuclide concentrations is of critical importance to end users in the nuclear sector to ensure correct classification prior to storage, recycling, reprocessing or disposal. Uncertainties in the characterisation of solid matrices and materials could lead to safety, quality and financial implications. Robust sample preparation methods are vital, in particular effective sample digestion, as under-estimated chemical yield recovery results in a corresponding under-estimation of activity levels. Borate fusion has been proven to effectively digest a range of complex sample matrices in the geosciences but is not used routinely elsewhere. In this study, we describe an automated procedure for borate fusion of multiple matrices encountered in nuclear decommissioning, containing diverse radionuclides over a range of activity concentrations. The impact of digestion flux, sample mass and sample to flux ratios are described, as well as the subsequent separation and measurement techniques. The results contribute to accurate and precise measurement of radionuclides in various matrices, as well as to characterisation of reference materials, providing greater confidence in nuclear industry programmes worldwide.
Zinc sulfide (ZnS) thin films in zinc-blende (ZB) and wurtzite (W) phases have been fabricated by pulsed laser deposition. 150 MeV Ni ion beam irradiation has been carried out at different fluences ranging from 1011 to 1013 ions/cm2 at room temperature for ion induced modifications. Structural phase transformation in ZnS from W to ZB phase is observed after high energy ion irradiation which leads to the decrease in bandgap. Generation of high pressure and temperature by thermal spike during MeV ion irradiation along the ion trajectory in the films is responsible for the structural phase transformation. 相似文献