Mass spectrometric identification of C60 fragmentation regimes under energetic Cs+ bombardment

TL;DR

This study uses mass spectrometry to identify three distinct fragmentation regimes of C60 fullerite under Cs+ ion bombardment, revealing how fragment emissions vary with ion energy and leading to full cage destruction.

Contribution

It provides a detailed analysis of C60 fragmentation regimes and the energy-dependent behavior of sputtered species under Cs+ bombardment, including the roles of recoils and cascades.

Findings

C2 is the dominant sputtered species at all energies.

Fragment emissions peak around 2 keV of Cs+ energy.

Fullerite transforms into amorphous carbon after sustained bombardment.

Abstract

Three C60 fragmentation regimes in fullerite bombarded by Cs+ are identified as a function of its energy. C2 is the major species sputtered at all energies. For E(Cs+) < 1 keV C2 emissions dominate. C2 and C1 have highest intensities between 1 and 3 keV with increasing contributions from C3 and C4. Intensities of all fragments maximize around 2 keV. Above 3 keV, fragments densities stabilize. The roles of and the contributions from direct recoils and collision cascades are determined. Maximum direct recoil energy delivered to the C60 fullerite cage is 210 eV at which only C2 emissions occur is identified and an explanation provided. The three fragmentation regimes under continued Cs+ bombardment eventually lead to complete destruction of the C60 cages transforming fullerite into amorphous carbon