Researchers at the Washington University of Science and Technology and researchers at the Surface Physics and Chemistry Laboratory Science and Technology have discovered the unique state of matter in glass solids. This pioneering work led by Professor Hai-bin Yu and Dr. Qi Wang proves the presence of liquid-like clusters in these materials, a finding published in the next Materials journal.
The study delves into the long-standing hypothesis of materials science that glass solids, especially metal glasses, contain internal areas where atoms exhibit liquid-like behavior. Previous evidence in these areas is largely indirect, making their presence and character somewhat speculative. This new study provides direct computational evidence for these clusters, called liquid-like dissipation clusters (LDCs), which show similar damping properties to liquids, but no diffusion motion is usually associated with liquid state.
Professor Yu said: “Our findings reveal the actual existence of local liquid-like dissipative clusters in glassy states, demonstrating damping factors similar to liquids and disappearing shear modulus.” The study highlights that these are the least developed The state only appears at low temperatures and does not involve the diffusion movement seen in typical liquids.
The team used molecular dynamics simulations to analyze the dissipative properties at the atomic level. The results show that these liquid-like clusters are the cause of the β’ relaxation process observed in metallic glass. β’ relaxation is a dynamic process that occurs at low temperatures and is associated with liquid-like movement in previous studies, but lacks a clear understanding of the mechanism. This study bridges the gap by providing a computational basis for the phenomenon.
Interestingly, studies show that these clusters are not diffuse, distinguishing them from other known relaxation processes in glass materials. This non-extended behavior is a key feature that sets the least developed countries apart and presents new perspectives on the internal dynamics of glass solids.
“The cryo-relaxation described in our study is not caused by atomic jumps and does not show diffusion behavior. The unique state of this condensation matter is dissipated, but does not diffuse,” explains Dr. Wang. This distinction may be for understanding and the mechanical properties of metal glasses are of great significance, especially at low temperatures.
Furthermore, studies have shown that the presence of these clusters can affect the mechanical behavior of metallic glasses, such as their plasticity. This study provides insights on why certain mechanical properties such as brittleness at moderate temperatures occur in these materials.
The discoveries in least developed countries not only validate long-term assumptions in the field, but also open up new avenues for research. The team plans to further study the structural characteristics associated with these clusters and explore their potential effects on other phenomena in glass materials, such as aging, crystallization and deformation.
This study marks an important step in a basic understanding of glass solids. It provides a solid foundation for the concept of liquid-like areas in these materials, challenges existing theories and has the potential to lead to new applications in materials science.
Journal Reference
Yu, Hai-bin and Qi Wang. “Liquid-like clusters in glassy solids are a unique state of matter: dissipated but not excluded.” Next Material 3 (2024): 100168. doi:
