prof. Vladimír Šepelák1,2
1Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
2Institute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, 040 01 Košice, Slovakia
online prednáška cez MS Teams
26. mája 2021 14:00
Mechanically induced chemistry (the so-called mechanochemistry) has a long history and continues to be of high importance. The presentation is focused on the mechanochemical phenomena in oxides, where an external mechanical force is exerted for the size reduction of solid particles even to the nanometer range, for the mixing and combination of chemical elements down to the atomic scale, and for the initiation or acceleration of solid state chemical reactions. The chemical reactions in oxides induced by mechanical action are categorized along the same lines that are commonly used in solid state chemistry and in chemistry, in general; they are either of homogeneous or of heterogeneous type. Homogeneous processes shall be exemplified here by the mechanically triggered formation of nonequilibrium structural (atomic) and magnetic (spin) configurations in complex oxides and by the mechanically induced phase transformations in binary oxides. Heterogeneous processes shall be illustrated with the specific case of the mechanically induced formation reactions (the so-called mechanosyntheses) of complex oxides.