On changes in the mechanism of chemical affinancy in the synthesis of compounds of refractory metals with oxygen group elements

DOI: 10.62564/M4-KP1521

Viktor Solntsev, Gennadii Bagliuk, Tetiana Solntseva, Kostiantyn Petrash

Frantsevich Institute for Problems of Materials Science National Academy of Science of Ukraine


Thermodynamic interpretation of chemical affinity as the tendency for chemical components to interact was given by Théophile de Donde. It manifests itself in systems up to the threshold of thermodynamic stability. In work [1], during the decomposition of unstable chalcogenides of refractory metals and during their interaction with metals of IVA, VA groups and chromium, both the existence and synthesis of unstable compounds of these metals with chalcogen type MeX3, MeX4 were established. An increase in the amount of chalcogen is observed during decomposition. To clarify the nature of the mechanisms of formation of chalcogenides beyond the threshold of thermodynamic stability, their interaction in complex metal systems containing the active reducing agent aluminum and diselenide was studied. The compacts were sintered in vacuum at temperatures above the existence of these chalcogenides. When studying the distribution of elements after sintering, the existence of titanium compounds of various stoichiometries, which is the basis of the composition, was established. No compounds of aluminum with selenium were found. Beyond the limit of thermodynamic stability, compounds are formed with metals that are less prone to interact with chalcogen. Moreover, these compounds are formed and exist at temperatures significantly higher than the region of their existence in the individual state. This phenomenon is due to the formation of a dissipative structure with a characteristic feature of dynamic stability. This type of stability occurs far from thermodynamic equilibrium due to the appearance of autowave processes in the reacting system. In such systems, self-oscillatory reactions occur, which was shown in [2, 3]. Namely, due to the catalytic properties of the seven elements, the manifestation of autowave properties is determined. Thus, the chemical affinity in these systems is determined by the tendency for the catalytic reproduction of atomic elements of the oxygen group.

Keywords
Chemical affinity, diselenide, dissipative structure

Acknowledgments
Not provided

References
[1] V.P. Solntsev. Development of work in the field of creating wear-resistant materials for structural purposes of space technology // Powder metallurgy, 2014.- No. 3/4.- P. 30-38. [2] V.P. Solntsev, V.V. Skorokhod, V.L. Baranov, G.O. Frolov, T.O. Solntseva. Mathematical modeling of highly nonequilibrium topochemical reactions in powder systems // Powder metallurgy, 2001.- No. 5/6.- P. 1-7. [3] V.P. Solntsev, V.V. Skorokhod, V.L. Baranov. Model of self-oscillatory topochemical reaction in an open system metal - diatomic gas // Reports of NASU - 2001 - No. 12 - P. 83-87.