Nonlinear electronic stopping power of channeled slow light ions in ZnSe: Evidence of energy loss caused by formation and breaking of chemical bond

Abstract Electronic stopping powerof helium ions in a semiconductor material ZnSe has been investigated through non-adiabatic dynamics simulations at energies of a few keV under channeling condition. The stopping poweris predicted to be proportional to velocity for the trajectory along middle axis of a 〈 1 1 0 〉 channel, as expected for the linear response theory accounts for election-hole pair creation. While for the off-center channeling trajectory, a counterintuitiveof electronic stopping powerversus velocity is observed. Our study, presented herein, finds a non-trivial connection between charge transfer and the force experienced by the projectile. Charge transfer can produce, throughout the collision process, additional force by continuously forming and breaking instantaneous chemical bonds between the projectile and the neighboring host atoms.