Improving atomic displacement and replacement calculations with physically realistic damage models

• Published in: Nature communications Vol. 9; no. 1; pp. 1084 - 8
• Main Authors: Nordlund, Kai, Zinkle, Steven J., Sand, Andrea E., Granberg, Fredric, Averback, Robert S., Stoller, Roger, Suzudo, Tomoaki, Malerba, Lorenzo, Banhart, Florian, Weber, William J., Willaime, Francois, Dudarev, Sergei L., Simeone, David
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14.03.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 639/301/1023/1026; 639/301/1034; 639/766/387; Atomic collisions; Atomic properties; Cascades; Collision dynamics; Computer simulation; Damage assessment; Displacements (lattice); Electron microscopy; Energetic particles; Humanities and Social Sciences; MATERIALS SCIENCE; Metals; Metals and alloys; multidisciplinary; Nuclear electric power generation; Nuclear energy; Nuclear physics; NUCLEAR PHYSICS AND RADIATION PHYSICS; Radiation; Radiation damage; Recombination; Science; Science (multidisciplinary); Theory and computation
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-03415-5

Atomic collision processes are fundamental to numerous advanced materials technologies such as electron microscopy, semiconductor processing and nuclear power generation. Extensive experimental and computer simulation studies over the past several decades provide the physical basis for understanding the atomic-scale processes occurring during primary displacement events. The current international standard for quantifying this energetic particle damage, the Norgett−Robinson−Torrens displacements per atom (NRT-dpa) model, has nowadays several well-known limitations. In particular, the number of radiation defects produced in energetic cascades in metals is only ~1/3 the NRT-dpa prediction, while the number of atoms involved in atomic mixing is about a factor of 30 larger than the dpa value. Here we propose two new complementary displacement production estimators (athermal recombination corrected dpa, arc-dpa) and atomic mixing (replacements per atom, rpa) functions that extend the NRT-dpa by providing more physically realistic descriptions of primary defect creation in materials and may become additional standard measures for radiation damage quantification. The Norgett−Robinson−Torrens displacements per atom model is the benchmark to assess radiation damage in metals but has well-known limitations. Here, the authors use molecular dynamics to introduce material-specific modifications to describe radiation damage more realistically.