Physico-Chemical nanomaterials science

Thermodynamic studied on competitive nanostructurization-amorphization effects driven by high-energy mechanical milling in arsenic selenide glasses
A. Kozdras1*, O. Shpotyuk2,3, Z. Bujňáková4, P. Baláž4, 
P. Demchenko5, Ya. Shpotyuk5,6, C. Boussard-Pledel7, B. Bureau7
1 Opole University of Technology,
75, Ozimska str., Opole, 45370, POLAND 
2 Institute of Physics of Jan Dlugosz University in Czestochowa,
13/15, al. Armii Krajowej, Czestochowa, 42200, POLAND
3 Vlokh Institute of Physical Optics,
23, Dragomanov str., Lviv, 79005, UKRAINE
4 Institute of Geotechnics of Slovak Academy of Sciences,
45, Watsonova str., Košice, 04001, Slovakia
5 Ivan Franko National University of Lviv,
1, Universytetska str., Lviv, 79000, Ukraine
6 Centre for Innovation and Transfer of Natural Sciences and Eng. Knowledge,
University of Rzeszow, 1, Pigonia str., Rzeszow, 35-959, POLAND
7 Equipe Verres et Céramiques, Institut des Sciences Chimiques de Rennes – UMR 6226 Université de Rennes 1, 35042 Rennes Cedex, France

Effect of high-energy ball mechanical milling in a dry mode on glassy arsenic selenides g-AsxSe100-x both under-stoichiometric (x≤40) and over-stoichiometric (x≥40) compositions was first examined with temperature-modulated DSC TOPEM® method complemented with X-ray powder diffraction analysis. 
It is shown that glass transition temperature Tg depressing is dominant in under-stoichiometric glasses, while an opposite enhancement is character for over-stoichiometric glasses. Milling occurs no effect near g-Se (x<20), but causes increase in the first sharp diffraction peak (FSDP) width for glasses with 20x40 due to destroyed remnants of inter-planar ordering. In over-stoichiometric g-AsxSe100-x (40x75), remnants of As4Se4 and As4Se3 molecules are more essentially changed under milling, facilitating formation of chain-like networks. This milling-driven amorphization results in drastic increase in the FSDP position and width, occurring fragmentation impact on correlation length of the FSDP-responsible entities. Milling-driven breakdown in intermediate-range ordering is concomitant with destruction of distant inter-atomic correlations belonging to quasi-crystalline planes contributing to the FSDP, while longer inter-atomic correlations become more dominant in their extended-range ordering.