Energy Retention in Thin Graphite Targets after Energetic Ion Impact

Abstract

High energy ion irradiation is an important tool for nanoscale modification of materials. In the case of thin targets and 2D materials, which these energetic ions can pierce through, nanoscale modifications such as production of nanopores can open up pathways for new applications. However, materials modifications can be hindered because of subsequent energy release via electron emission. In this work, we follow energy dissipation after the impact of an energetic ion in thin graphite target using Geant4 code. Presented results show that significant amount of energy can be released from the target. Especially for thin targets and highest ion energies, almost 40% of deposited energy has been released. Therefore, retention of deposited energy can be significantly altered and this can profoundly affect ion track formation in thin targets. This finding could also have broader implications for radiation hardness of other nanomaterials such as nanowires and nanoparticles.

Response of Bilayer and Trilayer Graphene to High-Energy Heavy Ion Irradiation

“…We conclude that the ion irradiation conditions were below the threshold for ion track formation both in BLG and TLG, even for the most energetic 23 MeV I 6+ beam. The dissipation of deposited energy from the nanometric thin films after the high-energy heavy ion impact makes ion tracks even more difficult to produce [ 24 , 28 , 33 , 34 ] and could be strongly contributing to the present study. Therefore, much more energetic heavy ion beams have to be used in applications relying on ion track formation (such as nanomembrane production [ 3 , 14 ]), when the ion track production efficiency should be close to 100%.…”

“…Bilayer (BLG) and trilayer graphene (TLG), often considered together as few-layer graphene, have also been recently investigated for their stability under ion irradiation [ 10 , 11 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Experimentally, their damage kinetics were found to be similar to that of single layer graphene (SLG), i.e., it is possible to describe it with the Lucchese model [ 8 ], though the size of defects in BLG and TLG appear to be somewhat smaller than in SLG [ 11 , 25 ].…”

“…In some cases, sputtering of the material may also occur [ 31 , 32 ]. Recently, corrections have been made that consider energy dissipation from the 2D material via the emission of electrons, thus lowering the amount of deposited energy up to 50% [ 24 , 33 , 34 ]. Clearly, this should make 2D materials such as graphene quite resistant to electronic energy loss, and therefore, the threshold for the ion track formation in graphene should be investigated more closely.…”

Charge State Effects in Swift-Heavy-Ion-Irradiated Nanomaterials

“…However, understanding and describing mechanisms leading to the formation of such nanostructures remain challenging. For example, the deposition and retention of SHI energy in thin films are difficult to model, but recently, some progress has been made [10][11][12].…”

High-Energy Heavy Ion Irradiation of Al2O3, MgO and CaF2

“…For the ion track to be formed, the density of deposited energy should exceed a material-dependent threshold [ 1 , 3 , 14 , 15 ]. Otherwise, the deposited energy will simply dissipate away, leaving the material unaltered.…”