Theoretical study of the channeling effect in the electronic stopping power of silicon carbide nanocrystal for low-energy protons and helium ions

摘要

Excited-states ab initio molecular dynamics model is employed to study the electronic stopping power of cubic silicon carbide nanocrystal when low-energy protons and helium ions are hyperchanneling in the <100>,<110> and <111> major crystal axes. The energy transfer processes between the ions and the electronic subsystem of the cubic silicon carbide nanocrystalline are studied. The channeling effect in the electronic stopping power is determined by the unique electronic structure of these channels. The velocity-proportional stopping power is predicted for both protons and helium ions in the low-energy region. The calculated stopping power is in a quantitative agreement with the experimental data up to the stopping power maximum. The deviations of the stopping power of helium ions from the linear proportionality are attributed to the electron transfer at higher velocities.