Glassy materials with enhanced thermal stability

Abstract

Abstract

Force networks and jamming in shear-deformed sphere packings

“…Details of our computations are provided in the Methods section and in the Suppmentary Information (SI). As described below, we obtain a precise, detailed geometric characterisation of the shear jamming transition that is at variance in key aspects with results for isotropic frictional jamming [12], and makes contact with analyses of rigidity in the rather different context of covalent network glasses [8]. We also obtain a mechanical characterisation, that is consistent with criteria for marginal stability analysed for frictionless packings but not hitherto applied to shear or frictional jamming.We first consider three dimensional sphere assemblies that are athermally sheared, and consider force and torque balance conditions as a function of strain to estimate the jamming strain, in the limit of infinite friction (friction coefficient µ → ∞).…”

“…We show that the shear jamming threshold satisfies the marginal stability condition recently proposed for jamming in frictionless systems [5]. We perform rigidity percolation analysis [6,7] for D = 2 and find that rigidity percolation precedes shear jamming, which however coincides with the percolation of overconstrained regions, leading to the identification of an intermediate phase analogous to that observed in covalent glasses [8].…”

“…We show that the shear jamming threshold satisfies the marginal stability condition recently proposed for jamming in frictionless systems [5]. We perform rigidity percolation analysis [6,7] for D = 2 and find that rigidity percolation precedes shear jamming, which however coincides with the percolation of overconstrained regions, leading to the identification of an intermediate phase analogous to that observed in covalent glasses [8].Jamming is the process by which disordered assemblies of particles become rigid and resist externally imposed stresses, for instance when their density becomes large enough. It has been widely investigated, both as a phenomenon that occurs in granular matter, and as a particular aspect of the emergence of rigidity in disordered matter, e. g. colloidal suspensions, foams, glass formers and gels and to understand the rheological properties of thermal and athermal driven systems [1-3, 5, 9, 10].…”

“…This observation has not previously been reported, although results that suggest such an intermediate regime have been reported for compressed granular packings [27]. The presence of an intermediate phase was previously observed in chalcogenides and oxide glasses [8,[28][29][30]. In the case of shear jamming, the role and implications of the intermediate phase is not clear and merit further investigation.…”

Correlating Melt Dynamics and Configurational Entropy Change With Topological Phases of AsxS100–x Glasses and the Crucial Role of Melt/Glass Homogenization

“…The fascination stems from fundamental investigations into their molecular structure that inherently control glass functionality examined as a function of network connectivity. These considerations have a close bearing on their Topological phases (Mantisi et al, 2015;Boolchand and Goodman, 2017). In recent years these materials have found a niche in select advanced applications as phase change memory materials (Raoux, 2009), in 3D X-point memory 1 (Tang et al, 2009;Malventano, 2017), as materials of choice for optical fibers and waveguides in infrared optics and Supercontinuum emission (Goncalves et al, 2018;Tremblay et al, 2018), amongst many others.…”