In-depth understanding of primary radiation damage in diamond induced by energetic particles: A molecular dynamics study

Diamond is an ideal semiconductor for extreme-environment applications due to its exceptional electrical, thermal, and mechanical properties, especially its remarkable radiation resistance. However, energetic particle irradiation can still induce lattice defects and degrade device performance, making it crucial to understand the underlying damage mechanisms. In this study, molecular dynamics simulations were employed to investigate the irradiation effects of several representative particle types on diamond. The results show that radiation damage is determined by multiple factors, including particle type, initial kinetic energy, incident position and incident angle. For instance, oxygen atoms produce a distinct “double-peak” defect evolution behavior due to the combined effects of thermal annealing and cascade collisions. Carbon atoms, introduced as a simplified model of neutron-induced primary knock-on atoms, generate fewer defects than oxygen but penetrate deeper into the lattice. Incident energy strongly dictates the damage patterns: in general, higher energy leads to more extensive defects, but the trend is moderated by particle type and energy-transfer efficiency. Specifically, highly energetic or lightweight particles may directly traverse the crystal, reducing damage efficiency and breaking the simple positive correlation between defect number and kinetic energy. Moreover, at fixed energy, the number of defects exhibits a rise-fall trend with increasing incident angle, peaking at 15° and 30°. This study provides a systematically comparable atomistic description of primary radiation damage in diamond under different incident conditions, and establishes a validated simulation framework and reference dataset for subsequent studies on defect evolution, multiscale modeling, and irradiation-related property changes.