Coulomb explosion as a probe to understand the mechanism of electron stripping from ions interacting with crystalline solids

Abstract

When an ion impinges on a solid, it rapidly undergoes a process in which its electrons are stripped away provided the velocity of the orbiting electrons is smaller than the projectile speed. Electron stripping determines any posterior behavior of the ions in the solid, and it is assumed that it takes place on the surface of the solid, but no information is available on the details of the process. Here we show, using the Coulomb explosion of C 2 + ions moving in Si as a tool, that electron stripping takes place in an orderly manner and that the number of electrons stripped, before charge equilibration, depends on a characteristic length. We also propose a relation capable of quantifying this dependence. We foresee these results as a starting point to a more general understanding of ion-solid interaction, with important consequences on ion beam analysis and modification techniques, and special significance in silicon technology.

Current status and future developments of the ion beam facility at the centre of micro-analysis of materials in Madrid

“…This range of energies is particularly suitable for the ion accelerator at CMAM (Fig. 3a) and, thus, there is an extensive collection of studies on this topic: the magnetic properties of graphite [32], the e↵ect of Coulomb explosion for molecular ions [33], the amorphization, structural changes and the optical properties of LiNbO 3 [34][35][36][37] and SiO 2 [38][39][40], the influence of an external magnetic field on the damage in Fe 90 Cr 10 [41] and Fe 85 Cr 15 alloys [42], the ion-induced elongation of Ag nanoparticles embedded in silica [43], and the improvement in electrical conductivity of LiTaO 3 and LiNbO 3 crystals [44]. The scientific and technological interest of diamond has been also a point of attention for the researchers at CMAM.…”

Interaction of H 2 + molecular beam with thin layer graphene foils*

“…[5,9,[23][24][25][26] In Ref. [27], the Rutherford backscattering energy spectrum of carbon fragments which were generated by a 1.847 MeV C + 2 cluster beam interacting with a silicon crystal target was used to measure the time when the Coulomb explosion just happened. It was reported that the electron stripping time was around 0.1 fs for T 100 spatial period, 0.12 fs for T 211 spatial period, and 0.2 fs for T 111 spatial period.…”