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Imeni Vladimira Il'icha Lenina, Russia

Granato A.V.,University of Illinois at Urbana - Champaign | Joncich D.M.,University of Illinois at Urbana - Champaign | Khonik V.A.,Voronezh State Pedagogical University
Applied Physics Letters | Year: 2010

An interpretation of a long-standing problem-the Lindemann melting rule-has been suggested within the framework of the interstitialcy theory. Melting is considered to be due to the rapid generation of thermodynamically equilibrium defects-dumbbell interstitials, which drastically decrease the shear modulus at the melting point. An analytical expression for the relationship between the thermal expansion coefficient and melting temperature coinciding with the Lindemann melting rule has been derived. The obtained results agree with available data on elemental substances. A correlation between the melting temperature and shear modulus has been discovered and explained within the framework of the same approach. © 2010 American Institute of Physics. Source

Liu Z.,Guangxi University for Nationalities | Van Loi N.,PetroVietnam University | Obukhovskii V.,Voronezh State Pedagogical University
International Journal of Bifurcation and Chaos | Year: 2013

In this paper, by using the topological degree theory for multivalued maps and the method of guiding functions, the existence and global bifurcation for periodic solutions of a class of differential variational inequalities are studied. © World Scientific Publishing Company. Source

Khonik V.A.,Voronezh State Pedagogical University | Kobelev N.P.,RAS Institute of Solid State Physics
Journal of Applied Physics | Year: 2014

It has been argued that the densification observed upon structural relaxation of metallic glasses can be explained not by the "free volume annihilation," as it is custom to consider, but by the annealing of interstitialcy-like "defects" frozen-in upon glass production. A simple expression for the enthalpy release due to relaxation of defect-induced dilatational energy has been proposed. The expression is shown to be in agreement with recent detailed experimental data on the heat release occurring upon structural relaxation of Au-based metallic glass [J. Bünz and G. Wilde, J. Appl. Phys. 114, 223503 (2013)]. © 2014 AIP Publishing LLC. Source

A review of the new approach to the understanding of the structural relaxation of metallic glasses based on the interstitialcy theory has been presented. The key hypothesis of this theory proposed by Granato consists of the statement that the thermodynamic properties of crystalline, liquid and glassy states are closely related to the interstitial defects in the dumbbell (split) configuration, called also interstitialcies. It has been argued that structural relaxation of metallic glasses takes place through a change of the concentration of interstitialcy defects frozen-in from the melt upon glass production. Because of a strong interstitialcy-induced shear softening, the defect concentration can be precisely monitored by measurements of the unrelaxed shear modulus. Depending on the relation between the current interstitialcy concentration c and interstitialcy concentration in the metastable equilibrium, different types of structural relaxation (decreasing or increasing c) can be observed. It has been shown that this approach leads to a correct description of the relaxation kinetics at different testing conditions, heat effects occurring upon annealing, shear softening and a number of other structural relaxation-induced phenomena in metallic glasses. An intrinsic relation of these phenomena with the anharmonicity of the interatomic interaction has been outlined. A generalized form of the interstitialcy approach has been reviewed. © 2015 by the authors; licensee MDPI, Basel, Switzerland. Source

Mitrofanov Yu.P.,Voronezh State Pedagogical University | Khonik V.A.,Voronezh State Pedagogical University | Granato A.V.,University of Illinois at Urbana - Champaign | Joncich D.M.,University of Illinois at Urbana - Champaign | And 2 more authors.
Applied Physics Letters | Year: 2012

High-precision isothermal measurements on strongly preannealed metallic glass reveal a decrease of the shear modulus to the metastable equilibrium value both in the glassy state far below the glass transition and in the supercooled liquid state near T g. The results obtained point out the existence of a low-temperature limit for the supercooled liquid, which is known as the Kauzmann pseudocritical temperature [W. Kauzmann, Chem. Rev. 43, 219 (1948)]. This finding experimentally questions the existence of the "Kauzmann paradox," which is widely discussed in the literature. © 2012 American Institute of Physics. Source

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