Model to Predict Dynamics of Glass -Tokyo University Scientists
Tokyo University scientists proposed a new model for predicting the dynamics of glass in relation to their local degree of atomic structural order. Researchers used computer simulations to demonstrate how this model enhances the understanding of the extra viscosity of glass on cooling. This work could assist in the manufacturing of glass, particularly that used in labware and electronic gadgets.
We had been producing glass since antiquity. But the physics behind the mobility of atoms in glass materials is exceptionally complicated and yet to be understood. Unlike crystalline solids where atoms are arranged in large repeating units, glasses have atoms that have no long-range ordering.
The glass flows like a liquid at high temperatures. This suggests that the atoms inside the glass have enough movement to glide past each other. But as the glass cools down, the mobility of atoms reduces, and finally, they turn into a disordered frozen liquid state. Glass would have been more stable if they had a crystalline structure. Experts describe glasses with respect to their structural relaxation time, which is the time to reach a stable state.
Using computer simulations, Tokyo University researchers defined the structural order parameter of glass, which depends only on the local configuration and immediate neighbors. The structural order parameter measures the deviation of atoms from the most efficiently packed neighboring atoms. The researchers could predict the structural relaxation time from this value even though the relaxation depends on many physical factors.
They confirmed the correlation between local ordering and overall dynamics through comprehensive computer simulations. This is a unique attribute of glass that, unlike crystalline solids. The information about how the relationship between locations grows in size, such that the dynamics at the atomic level begin to have cooperativity over an extended region, is provided by the model. The findings from this research will help to manufacture stronger and durable glass materials.
Nature Communications published the research as “Structural order as a genuine control parameter of dynamics in simple glass formers.”