The instantaneous shear modulus in the shoving model

Area of Science:

• Materials Science
• Condensed Matter Physics

Background:

• Understanding the temperature dependence of viscous liquid relaxation times is crucial.
• The shoving model offers a framework for this non-Arrhenius behavior.

Purpose of the Study:

• To clarify the physical meaning of the instantaneous shear modulus G(∞) in the shoving model.
• To compare experimental data of metallic glasses with different versions of the shoving model.

Main Methods:

• Analysis of the shoving model's instantaneous shear modulus G(∞).
• Comparison of model predictions with experimental data for metallic glasses.
• Evaluation of shear-modulus and energy-landscape formulations of the shoving model.

Main Results:

• The instantaneous shear modulus G(∞) corresponds to the experimentally measurable high-frequency plateau modulus.
• The original shoving model showed a correlation with the Poisson ratio.
• The energy-landscape formulation eliminated this correlation, with the bulk modulus playing a minor role.

Conclusions:

• The high-frequency plateau modulus is the relevant parameter for the shoving model.
• The energy-landscape formulation provides a more robust description of viscous liquid dynamics in metallic glasses.
• This work refines the application of the shoving model to understand material properties.