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تسجيل مستخدم جديدRevealing the role of molecular rigidity on the fragility evolution of glass-forming liquids
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If quenched fast enough, a liquid is able to avoid crystallization and will remain in a metastable supercooled state down to the glass transition, with an important increase in viscosity upon further cooling. There are important differences in the way liquids relax as they approach the glass transition, rapid or slow variation in dynamic quantities under moderate temperature changes, and a simple means to quantify such variations is provided by the concept of fragility. Here, we report molecular dynamics simulations of a typical network-forming glass, Ge-Se, and find that the relaxation behaviour of the supercooled liquid is strongly correlated to the variation of rigidity with temperature and the spatial distribution of the corresponding topological constraints which, ultimately connect to fragility minima. This permits extending the fragility concept to aspects of topology/rigidity, and to the degree of homogeneity of the atomic-sale interactions for a variety of structural glasses.
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When a liquid is cooled below its melting temperature it usually crystallizes. However, if the quenching rate is fast enough, it is possible that the system remains in a disordered state, progressively losing its fluidity upon further cooling. When t
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