Narrow Results

E-beam irradiation is one of the favorite methods of recent years and it can deliver the irradiation dose in just a few seconds to form nanoparticles. It is possible to obtain nanoparticles with different properties by changing the experimental conditions, as well as radiolytic reduction process can be adjusted through accelerators, it is possible to obtain oxides and hydroxides of metal nanoparticles. This paper reports the investigation of high-energy electron beams (EBs) on the crystal structure of 40–60 nm nanoscale Al particles. The crystal structure of the samples was calculated using the Rietveld method in the FullProf program. Structure analysis of three different irradiated ($4.16\times 10^{16}{\mathrm{\text{cm}}}^{-2}$, $1.20\times 10^{17}{\mathrm{\text{cm}}}^{-2}$, $1.03\times 10^{18}{\mathrm{\text{cm}}}^{-2}$) Al samples and nonirradiated Al samples was performed by XRD. Occurring energy during the process of linear electron acceleration was around $\sim$2–3 MeV. All samples were irradiated at room temperature. In addition to STP, temperature changes can be observed when the particles are exposed to high energy for a long time. At STP, nanoscale Al particles combine with the oxygen of the air and form Al₂O₃. Also, X-ray diffraction study showed that the instability does not only belong to Al particles but also to Al₂O₃ in view of the fact that precarious Al(OH)₃ crystal structures were observed. Thus, radiation dependence of lattice parameters was obtained, the mechanism of change of lattice parameters was determined due to radiation.

In this research work, the effects on the structural and optical properties of e-beam irradiated Al nanoparticles (Al-NPs) by three field sizes, $4.16\times 10^{16}{\mathrm{\text{cm}}}^{-2}$, $1.20\times 10^{17}{\mathrm{\text{cm}}}^{-2}$ and $1.03\times 10^{18}{\mathrm{\text{cm}}}^{-2}$ fluence were studied. As a result of systematic observations, it has been possible to study the effect of electron beam on X-ray diffraction (XRD), infrared (IR) spectroscopy and Raman band modifications and, consequently, on the crystal structure and atomic dynamics of Al-NPs. The XRD method determined that Al-NPs are combined with water molecules in the air to form aluminum hydroxide (Al(OH)₃) groups. The Al(OH)₃ formation was not observed in any of the samples irradiated with three different fluences, $4.16\times 10^{16}{\mathrm{\text{cm}}}^{-2}$, $1.20\times 10^{17}{\mathrm{\text{cm}}}^{-2}$ and $1.03\times 10^{18}{\mathrm{\text{cm}}}^{-2}$, respectively. Confirmation of these results was also shown in the method of IR spectroscopy. While 12 vibrational modes were observed in the non-irradiated samples, only the vibrational modes corresponding to Al–Al bonds were observed in $4.16\times 10^{16}{\mathrm{\text{cm}}}^{-2}$, $1.20\times 10^{17}{\mathrm{\text{cm}}}^{-2}$, and $1.03\times 10^{18}{\mathrm{\text{cm}}}^{-2}$ fluence irradiated samples. It was determined by the Raman spectroscopy method that a low concentration of Al(OH)₃ remains in the samples irradiated with $4.16\times 10^{16}{\mathrm{\text{cm}}}^{-2}$ fluence. Only $1.20\times 10^{17}{\mathrm{\text{cm}}}^{-2}$ and $1.03\times 10^{18}{\mathrm{\text{cm}}}^{-2}$ fluence irradiated samples were found to correspond to the XRD and IR spectra, and Raman vibrational modes corresponding to Al–Al bonds were observed. In addition, electron irradiation is a suitable technique to increase the optical properties of nanoparticles by controlling the size of the particles.