Cerium is a silvery-white metallic element that has found many applications in chemical-mechanical planarization and high-end optical surfaces. It also plays a role in catalytic converters to reduce nitrogen oxide and carbon monoxide emissions from cars.
A little-known element, cerium is a soft and ductile metal. It tarnishes in moist air and reacts with water to form cerium hydroxide plus hydrogen gas.
When the surface of the metal is damaged, it ignites with a bright flash of light. Small particles of the metal can also ignite if a knife scratches them.
In this way, cerium is the second most reactive of the lanthanides. Its yellow oxide layer, which protects the pure metal from oxygen oxidation, catches fire at temperatures above 150 degrees C.
This explains why the metal is used as a catalyst for catalytic oxidation of exhaust gases from automobiles.
X-ray imaging can also help scientists better understand the material response of materials under extreme conditions, such as those created by shockwaves or explosions. Researchers from Los Alamos National Laboratory, Argonne National Laboratory and National Security Technologies LLC generated shockwaves in cerium samples using a state-of-the-art X-ray imaging system called the IMPact system for ULtrafast Synchrotron Experiments (IMPULSE).
The researchers also have developed an equation-of-state to predict cerium’s response to shock. Their findings provide a foundation for understanding how strength evolves during dynamic loading. This may eventually lead to the development of strength-aware multi-phase EOS to predict the behavior of matter under various extreme conditions.