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Information × Registration Number 0211U006885, 0109U006378 , R & D reports Title Interphase boundaries during phase separation in bulk metallic glasses: theory and experiment. popup.stage_title Head Bakai Olexander Stepanovich, Доктор фізико-математичних наук Registration Date 12-05-2011 Organization National Science Center "Kharkiv Institute of Physics and Technology popup.description2 The subject of investigation is the structure of interphase boundaries in bulk metallic glasses. In order to clarify fundamental laws of interface boundaries formation at liquid-solid phase transitions concomitant to the growth of bulk amorphous alloys, the theoretical methods of statistical physics of condensed matter and physics of phase transitions (and, particularly, the methods of the heterophase state theory) are used. The thermodynamics and cooperative dynamics of the heterophase liquid solidification process were first considered theoretically taking into account the frustration and bulk interaction of non-crystalline solid-like fluctuons. It has been found that the mathematical form of the system equilibrium equations remains unchanged but the thermodynamic coefficients are renormalized when these factors are included into the fluctuon model. As a result, the polyamorphous phase change in the liquid are strongly affected by frustration. We have found that the characteristic temperature of phase coexistence in heterophase liquid is reduced by frustration while being contrariwise increased by the bulk interaction of fluctuons. It has been shown that the frustrated heterophase fluctuations depress the crystallization of the liquid and, because of frustration, the "liquid-glass" transition occurs in a finite temperature range. It has been shown that the width of this range is proportional to the difference of the frustration parameter and the bulk interaction energy while outside this range, the rate of cooperative alpha-relaxation of the fluid obeys the Arrhenius equations with different activation energies. The expressions for the characteristic Kauzmann and Vogel-Fulcher temperatures have been obtained within the framework of the developed model of heterophase fluctuations. These temperatures have been found to be close with good accuracy. Thus, the experimentally observed correlation between the empirical glass transition temperature, the Vogel-Fulcher temperature and the temperature of an "ideal" liquid-glass transformation has been explained theoretically. Product Description popup.authors Бакай Олександр Степанович Дюльдя Сергій Володимирович Лазарєв Микола Петрович popup.nrat_date 2020-04-02 Close