title: Microstructure Hierarchical Model of Competitive e+-Ps Trapping in Nanostructurized Substances: from Nanoparticle-Uniform to Nanoparticle-Biased Systems.
abstract: Microstructure hierarchical model considering the free-volume elements at the level of interacting crystallites (non-spherical approximation) and the agglomerates of these crystallites (spherical approximation) was developed to describe free-volume evolution in mechanochemically milled As4S4/ZnS composites employing positron annihilation spectroscopy in a lifetime measuring mode. Positron lifetime spectra were reconstructed from unconstrained three-term decomposition procedure and further subjected to parameterization using x3-x2-coupling decomposition algorithm. Intrinsic inhomogeneities due to coarse-grained As4S4and fine-grained ZnS nanoparticles were adequately described in terms of substitution trapping in positron and positronium (Ps) (bound positron-electron) states due to interfacial triple junctions between contacting particles and own free-volume defects in boundary compounds. Compositionally dependent nanostructurization in As4S4/ZnS nanocomposite system was imagined as conversion from o-Ps trapping sites to positron traps. The calculated trapping parameters that were shown could be useful to characterize adequately the nanospace filling in As4S4/ZnS composites.
authors.affiliation: Jan Dlugosz University, al. Armii Krajowej, 13/15, 42201, Czestochowa, Poland. olehshpotyuk@yahoo.com.|Vlokh Institute of Physical Optics, 23, Dragomanov str., 79005, Lviv, Ukraine. olehshpotyuk@yahoo.com.
authors.forename: Oleh
authors.initials: O
authors.lastname: Shpotyuk
authors.affiliation: Opole University of Technology, 75, Ozimska str., 45370, Opole, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Ingram
authors.affiliation: Institute of Geotechnics of Slovak Academy of Sciences, 45, Watsonova str., 04001, Košice, Slovakia.
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Bujňáková
authors.affiliation: Institute of Geotechnics of Slovak Academy of Sciences, 45, Watsonova str., 04001, Košice, Slovakia.
authors.forename: Peter
authors.initials: P
authors.lastname: Baláž
keywords: Mechanochemical milling; Nanocomposite; Nanoparticles; Positron annihilation