The report will review recent achievements in application of positron annihilation spectroscopy (PAS) using a variable-energy positron beam or slow positron beam spectroscopy (SPBS) [1-4] as a key technique that shows a completely new way to understand the radiation-induced processes and defect structure in a variety of materials important for practical use.
In this context, PAS-SPBS is demonstrated as a powerful experimental tool applied, in particular, to polymer nanocomposites with carbon nanostructures and metal nanoparticles (MNPs) (see also [5]). The results concerning 40 keV boron-ion-implanted polymethylmethacrylate (B:PMMA) and 30 keV silver-ion-implanted polymethylmethacrylate (Ag:PMMA) will be discussed. The possibilities of PAS-SPBS techniques use to clarify the mechanisms of a formation of carbon nanostructures in B:PMMA and Ag NPs in Ag:PMMA are highlighted.
Another example of PAS-SPBS application is connected with study the radiation-induced processes in U4Al7Si5 compound subjected to 30 keV Ar+ implantation. In [6] it was established that in materials, whose composition includes atoms with very different masses, under ion bombardment in certain energy intervals so called heavy clusters are formed. At this stage the formation of U clusters in mentioned compound due to a disordering of crystal structure upon Ar ion implantation could be suggested from the obtained Doppler broadening PAS-SPBS results.
[1] T. Kavetskyy et al., J. Phys. Chem. B 118, 4194 (2014).
[2] T.S. Kavetskyy et al., Low Temp. Phys. 40, 747 (2014).
[3] T.S. Kavetskyy, A.L. Stepanov, in: Radiation Effects in Materials, InTech, 2016, P. 287-308.
[4] T. Kavetskyy et al., J. Phys.: Conf. Ser. 791, 012028 (2017).
[5] G. Panzarasa et al., Nanotechnology 27, 02LT03 (2016).
[6] A. Kiv et al., Intern. J. Adv. Comp. Techn. 4, 81 (2015).