How fractals jam glassy materials

A fractal pattern in the energy landscape of glass molecules may influence the way the molecules arrange themselves and could help to explain how other materials behave.

Prokofiev/Wikimedia Commons (CC BY-SA 3.0)

Unlike molecules in a crystal lattice, the molecules in glass don’t have regular positions, even though glass is a solid. Scientists think that glass molecules don’t flow, as they would in a liquid, because the particles are caged by each other and don’t have enough energy to overcome a threshold known as the energy barrier, which is like a hill. Instead, the molecules stay in valleylike depressions.

But the energy landscape of glass molecules may not be as simple as hills and valleys, scientists argue April 24 in Nature Communications. As the molecules are compressed, the valleys break down into geometric patterns known as fractals. The finding could help explain what happens when glassy materials are deformed or when coffee beans in a container jam, the scientists say.

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

More Stories from Science News on Materials Science

From the Nature Index

Paid Content