Cool Science: Understanding How Materials Behave in Extreme Environments

Radiation induced damage causes premature failure of materials in critical and extreme environments. Understanding the mechanisms that produce damage and designing materials in ways that mitigates such damage is an important field of study in the fields of mechanical, aerospace, and nuclear engineering. The Djamel group, along with collaborators, looked at thin iron films and how ion irradiation (which is used to simulate neutron irradiation without causing residual radioactivity) damaged these films. They used the FIB and TEM in the AIF to prepare and characterize the defect structures within these iron thin film samples before and after ion irradiation. While transmission electron microscopy (TEM) is an extremely high spatial resolution technique, it does not have sufficient spatial resolution to resolve the point defects and vacancy clusters that are created by radiation damage. To study these one dimensional defects, the researchers used positron annihilation lifetime spectroscopy (PALS) to understand the number and spatial distribution of the smallest defects. By combining TEM and PALS, the researchers were able to study the larger and the smallest defects in these iron films both before and after ion irradiation, thus revealing the evolution of the materials microstructure with irradiation dose. These results improve the understanding of how materials behave in extreme environments.

Learn more about the larger collaborations and center that supported this work by watching the YouTube video below.