Evrim Yazgin
Cosmos science journalist
A common mineral and earthquake and avalanche statistics can be used to measure the impact of hostile environmental events on materials.
Such studies would provide important information about the degradation and failure of materials used for advanced solar panels, geological carbon capture and infrastructure such as buildings, roads and bridges.
Muscovite is the most common type of mica. It is known for its flaky, layered sheets.
The mineral can be found in granites and gneisses and contains aluminium and potassium. It is used in many materials science applications including the construction of high-temperature furnaces and oven windows.
The study published in Nature Communications offers a new use for muscovite.
Engineers need to be able to test different materials’ response to stress and strain in order to make infrastructure that can withstand environmental events like earthquakes.
They also want to know how chemical reactions between minerals and groundwater along faults might slowly weaken rocks and lead to sudden failure. This process is called chemomechanical weakening.
“While previous attempts to quantify the effect of chemomechanical weakening in engineered materials have relied on complex molecular dynamics models requiring significant computational resources, our work instead emphasizes the bridge between laboratory experiments and real-world phenomena like earthquakes,” says study lead Jordan Sickle, a graduate student at the University of Illinois Urbana-Champaign in the US.
“Muscovite was chosen for this study mainly because of this material’s extreme flatness,” says Karin Dahmen, a professor at Illinois. “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 especially important.”
The researchers tested chemomechanical weakening on muscovite surfaces by exposing samples to different conditions. This included dry, and submersed in solutions of deionised water and salt water with pH 9.8 or 12.
Dry muscovite, they found, can deform more before it fails.
“The results of this work allow researchers to test material failure more quickly than high-powered, detailed simulation models,” Sickle says. “By showing that we can observe the same results by using the statistical models already in place for earthquakes, researchers will be able to perform more material analysis than previously possible.”
