title: Revealing the role of molecular rigidity on the fragility evolution of glass-forming liquids.
abstract: 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 the fragility minima. This permits extending the fragility concept to aspects of topology/rigidity, and to the degree of homogeneity of the atomic-scale interactions for a variety of structural glasses.
authors.affiliation: Laboratoire de Physique Théorique de la Matière Condensée, Paris Sorbonne Universités-UPMC, Boite 121, 4, Place Jussieu, 75252 Paris Cedex 05, France.|Physique des Solides, Interfaces et Nanostructures &CESAM, B5, Université de Liège, B4000 Sart-Tilman, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Yildirim
authors.affiliation: Physique des Solides, Interfaces et Nanostructures &CESAM, B5, Université de Liège, B4000 Sart-Tilman, Belgium.
authors.forename: J-Y
authors.initials: JY
authors.lastname: Raty
authors.affiliation: Laboratoire de Physique Théorique de la Matière Condensée, Paris Sorbonne Universités-UPMC, Boite 121, 4, Place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: M
authors.initials: M
authors.lastname: Micoulaut