Surprisingly high irradiation-induced defect mobility in Fe3O4 as revealed through in situ transmission electron microscopy

• Published in: Materials characterization 2022-03, Vol.187
• Main Authors: Owusu-Mensah, Martin, Cooper, Jacob, Morales, Angelica Lopez, Yano, Kayla, Taylor, Sandra D., Schreiber, Daniel K., Uberuaga, Blas Pedro, Kaoumi, Djamel
• Format: Article
• Language: English
• Subjects: defect mobility; Fe oxide; in-situ transmission electron microscopy; ion irradiation; irradiation-induced defects; MATERIALS SCIENCE
• ISSN: 1044-5803; 1873-4189

Radiation-induced defects are expected to change the corrosion kinetics when a material is exposed to a corrosive environment. Characterization of the defects forming under irradiation and their ability to move/diffuse is therefore key to understanding how they impact the corrosion kinetics and possibly mechanisms. For that matter, Fe/Fe3O4 interfaces were irradiated using 1 MeV Kr2+ at temperatures of 273 K (25 °C), 573 K (300 °C) and 773 K (500 °C) to a maximum dose of 10 dpa (as measured in the Fe matrix) in situ in a transmission electron microscope. The evolution of the microstructure was followed as a function of the dose and temperature. The formation of defects was followed in the metal and the oxide as well as at the metal/oxide interface and characterized in terms of size and density. Additionally, the dynamic observation of the spatial distribution of the defects allowed for a qualitative assessment of the mobility of defects in the oxide as a function of temperature, revealing evidence for enhanced mobility even more so than in the Fe matrix. Mechanisms of induced defect mobility in the spinel are discussed to account for the observations.