Insight into Elastic Properties of Binary Alkali Silicate Glasses; Prediction and Interpretation through Atomistic Simulation Techniques

Abstract

Molecular dynamics simulations and energy-minimization techniques have been applied for the first time to determine the whole set of elastic properties (Young's modulus, shear modulus, bulk modulus, and Poisson's ratio) of alkali silicate glasses with different ion modifiers (Li, Na, and K) in the range 0-30 mol % alkaline oxide. Excellent agreement has been found between the simulation results and the experimental data. The peculiar behavior of the Li-containing glasses with respect to the Na and K ones is extensively discussed in terms of the glass structural features. It is found that the elastic property variation as a function of alkali addition can be explained by three concurrent factors: (1) depolymerization of the silica network; (2) increasing the cohesion of the glass by the establishment of alkali-NBO bonds; and (3) decreasing the free volume with consequent increasing of the glass packing density.

Insight into the structure of vanadium containing glasses: A molecular dynamics study

“…A cutoff of 5.5 Å has been used for the short range interactions. Similar conditions have been already validated and tested with success on different inorganic glass systems [36,46].…”

“…Unfortunately, most of MD simulations have been applied to study the structure, transport and mechanical properties of alkaline-, [36][37][38][39][40][41][42][43][44][45] alkaline-earth [46] and phospho-silicate glasses [47][48][49][50][51][52][53][54][55][56] but only a few of them were devoted to glasses doped by TM ions and V-containing glasses [57,58].…”

Fracture toughness of calcium–silicate–hydrate from molecular dynamics simulations

“…The full elastic tensor C ij was computed for a bulk system, before the introduction of the initial crack. The elements of the stiffness tensor are obtained by calculating the curvature of the potential energy U with respect to small strain deformations i [33]:…”

Densified network glasses and liquids with thermodynamically reversible and structurally adaptive behaviour

“…In addition, the relaxation time t at T ¼ 2,000 K is found to evolve similarly. Here one assumes the Maxwell relation Z ¼ G N t with G N the instantaneous shear modulus, and a separate computation of the viscosity Z, and G N from the shear strain/shear stress response 20 provides the evolution of t with respect to pressure P or constraint density n c . A deep minimum is found in the relaxation time (tB2-3 ps) in the region 3.0on c o3.2 (bottom inset of Fig.…”