Cooperative motion by atoms protects glass from fracturing

We've all experienced the moment of panic when a glass slips from our hands, shattering into pieces upon hitting the ground. What if this common mishap could become a thing of the past?

Now, a new discovery by researchers at Tohoku University has offered insights into how glass resists breakage, potentially paving the way for highly durable, break-resistant materials. The breakthrough has wide ranging implications for glass-related industries.

Details of their findings were published in the journal Acta Maeterialia on December 2, 2024.

"Glass, while strong, is prone to breaking when stress exceeds its tolerance, but interestingly, the movement of atoms and molecules within glass can relax internal stress, making the material more resistant to fractures," points out Makina Saito, an associate professor at Tohoku University's Graduate School of Science. "Although we know that some atoms 'jump' into nearby empty spaces, how this process alleviates stress has long been a mystery."

Saito and his colleagues, who comprised researchers from Kyoto University, Shimane University, the National Institute for Materials Science, and the Japan Synchrotron Radiation Research Institute, uncovered a previously unknown mechanism of stress relaxation in ionic glass, a model system of glass.

Their research utilized state-of-the-art synchrotron radiation experiments and computer simulations to observe atomic motions in glass on a nanosecond-to-microsecond timescale.

The team discovered that when some atoms within the glass 'jump' into nearby empty spaces, surrounding groups of atoms slowly move together to fill the void. This interplay of atomic jumps and collective motion reduces internal stress, protecting the glass from breaking under external force.

"Our results have far-reaching implications for industries such as consumer electronics, construction, and automotive manufacturing, where break-resistant glass is essential," adds Saito.

Looking ahead, the research team plans to explore whether similar atomic mechanisms operate in other types of glass. Their ultimate goal is to establish universal guidelines for designing glass with superior impact resistance, which could revolutionize applications requiring durable materials.