Tracking the Connection between Disorder and Energy Landscape in Glasses Using Geologically Hyperaged Amber

Area of Science:

• Materials Science
• Condensed Matter Physics
• Geochemistry

Background:

• Fossil amber, aged over 110 million years, serves as a natural laboratory for studying amorphous materials.
• Understanding the evolution of glasses' properties over geological timescales is crucial for materials science.

Purpose of the Study:

• To investigate the link between the potential energy landscape and the structural/vibrational properties of glasses.
• To analyze the effects of natural aging (hyperaging) on amber's properties.

Main Methods:

• X-ray scattering techniques were applied to fossil amber samples.
• Samples were analyzed before and after annealing to erase thermal history.

Main Results:

• Hyperaging leads to a depletion of vibrational density of states in the terahertz region, affecting acoustic wave properties.
• Amber densification occurred, with structural implications distinct from hydrostatic compression.
• Approaching the potential energy landscape minimum reduced disorder and increased long-range correlation in the elastic matrix.

Conclusions:

• A direct correlation exists between a glass's potential energy landscape and its structural and vibrational characteristics.
• Hyperaging significantly modifies the properties of amorphous materials over geological timescales.
• Fluctuating elasticity theory provides a framework for understanding these aging-induced changes in glasses.