CHAMPAIGN, Ill. — Materials scientists can now use information from a very common mineral and well-established earthquake and avalanche statistics to quantify how hostile environmental interactions can affect the degradation and failure of materials used for advanced solar panels, geological trapping of carbon and infrastructure such as buildings, roads and bridges.

The new study, led by the University of Illinois Urbana-Champaign in collaboration with Sandia National Laboratories and Bucknell University, shows that the amount of deformation caused by locally applied stress on the surface of muscovite mica is controlled by the physical state of the mineral’s surface. and follows the same statistical dynamics observed in earthquakes and avalanches.

The results of the study are published in the journal Communication of nature.

When selecting materials for engineering applications, scientists want to know how the surface of that material will interact with the environment in which it will be used. Similarly, geologists want to understand how chemical reactions between minerals and groundwater along faults could slowly weaken rocks and lead to rapid bursts of mechanical failure due to a process called chemomechanical weakening.

“While previous attempts to quantify the effect of chemomechanical weakening in engineered materials have relied on complex molecular dynamics models that require significant computational resources, our work instead emphasizes the bridge between laboratory experiments and real-world phenomena, how there would be earthquakes,” said graduate student Jordan Sickle. who conducted the study with Illinois physics professor Karin Dahmen.

“Muscovite was chosen for this study mainly because of the extreme flatness of this material,” said Dahmen. “Each of its flaky layers is flat down to the atomic level. Because of this flatness, the interaction between the surface of this material and its environment is particularly important.”

To measure the chemomechanical weakening on muscovite surfaces, Sandia National Laboratories exposed samples to different chemical conditions—dry, immersed in deionized water, and in salt solutions with a pH of 9.8 and 12. During exposure, an instrument known as the name nanoindenter pierced the mineral surface and recorded the displacements or defects in the material under controlled mechanical loads.

The researchers found that under dry conditions, muscovite can deform more before failing than under wet conditions. At failure, the specimens in each condition release their stored elastic energy. The study reports that when muscovite is exposed to a basic solution at pH 9.8 or 12, the top layer weakens and less energy can be stored before failure occurs, which is reflected in the explosion statistics.

“The results of this work allow researchers to test material failure faster than detailed high-powered simulation models,” Sickle said. “By showing that we can observe the same results using already existing statistical models for earthquakes, researchers will be able to perform analyzes of materials with greater throughput than previously possible.”

The US Department of Energy and Sandia National Laboratories support this research.

Editor’s note:

To contact Karin Dahmen, call 217-244-8873; email [email protected].

The paper “Quantification of Chemomechanical Weakening in Muscovite Mica with a Simple Micromechanical Mode” is available online. DOI: 10.1038/s41467-024-53213-5. Physics is part of Grainger College of Engineering.