The charge exchange of slow highly charged ions at surfaces unraveled with freestanding 2D materials

A compact electron beam ion source for highly charged ion experiments at large-scale user facilities

“…In a surface analysis setup, which relies on the detection of charged particles emitted or reflected from a surface, such as a secondary ion mass spectroscopy (SIMS) or low-energy ion scattering (LEIS) apparatus, e.g. replacing the commercial ion source with a compact EBIS would allow to enhance the ratio of charged to neutral particles and thus boost the detection efficiency by orders of magnitudes [33]. This would make SIMS a quantitative technique without the use of calibration standards [34].…”

Model for Nanopore Formation in Two-Dimensional Materials by Impact of Highly Charged Ions

“…For example, when a freestanding vdW-MoS 2 /graphene heterostructure was recently irradiated with Xe 38+ ions, it was found that nanometer-sized pores formed only in the MoS 2 monolayer facing the ion beam while the graphene beneath remained intact . The known high material selectivity in the deposition of potential energy of HCIs had been noticed earlier, , but to explore its mechanisms in more detail is essential for a targeted application in the processing of vdW heterostructures on the nanoscale: e.g., for water purification or filtering CO 2 and other gases. , To test the response of 2D materials to the deposition of large amounts of potential (i.e., electronic) energy, experiments have been conducted in which HCIs were directed on such targets. , A range of materials was covered from conducting single-layer graphene (SLG), for which the ejection of numerous electrons (multiple times the initial HCI charge Q in ) and structural integrity was observed, ,, to semiconducting MoS 2 , which disintegrates around the point of ion impact in combination with the emission of only a few electrons . For the latter material nanopores with a diameter of a few nanometers were observed with the mean radius depending on the initial charge state of the HCI .…”

“…13,14 To test the response of 2D materials to the deposition of large amounts of potential (i.e., electronic) energy, experiments have been conducted in which HCIs were directed on such targets. 15,16 A range of materials was covered from conducting single-layer graphene (SLG), for which the ejection of numerous electrons (multiple times the initial HCI charge Q in ) and structural integrity was observed, 9,10,17 to semiconducting MoS 2 , which disintegrates around the point of ion impact in combination with the emission of only a few electrons. 18 For the latter material nanopores with a diameter of a few nanometers were observed with the mean radius depending on the initial charge state of the HCI.…”

Charge exchange of slow highly charged ions from an electron beam ion trap with surfaces and 2D materials

“…Only then one will be able to systematically tune parameters such as ion species, kinetic energy and charge as well as irradiation geometry and sample temperature conditions in order to create some intended structures. For this, it is necessary to extract HCIs from the source, which is done not only at big research facilities like at GSI Darmstadt [18], the Multicharged Ion Research Facility (MIRF) at Oak Ridge National Laboratory [19], the Heavy Ion Research Facility in Lanzhou (HIRFL) [20] or at the High-Intensity heavy-ion Accelerator Facility (HIAF) in Huizhou (China) [21], but also in lab-size EBITs: The ions then can be directed towards gas [22][23][24][25][26] or solid targets [27][28][29][30][31] and HCI interaction with other molecules and solids can be studied. For the latter, a multitude of data has been achieved using bulk materials, focusing, e.g.…”