title: Interfacial carbon nanoplatelet formation by ion irradiation of graphene on iridium(111).
abstract: We expose epitaxial graphene (Gr) on Ir(111) to low-energy noble gas ion irradiation and investigate by scanning tunneling microscopy and atomistic simulations the behavior of C atoms detached from Gr due to ion impacts. Consistent with our density functional theory calculations, upon annealing Gr nanoplatelets nucleate at the Gr/Ir(111) interface from trapped C atoms initially displaced with momentum toward the substrate. Making use of the nanoplatelet formation phenomenon, we measure the trapping yield as a function of ion energy and species and compare the values to those obtained using molecular dynamics simulations. Thereby, complementary to the sputtering yield, the trapping yield is established as a quantity characterizing the response of supported 2D materials to ion exposure. Our findings shed light on the microscopic mechanisms of defect production in supported 2D materials under ion irradiation and pave the way toward precise control of such systems by ion beam engineering.
authors.affiliation: II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Herbig
authors.forename: E Harriet
authors.initials: EH
authors.lastname: Åhlgren
authors.forename: Wouter
authors.initials: W
authors.lastname: Jolie
authors.forename: Carsten
authors.initials: C
authors.lastname: Busse
authors.forename: Jani
authors.initials: J
authors.lastname: Kotakoski
authors.forename: Arkady V
authors.initials: AV
authors.lastname: Krasheninnikov
authors.forename: Thomas
authors.initials: T
authors.lastname: Michely
keywords: DFT; STM; graphene; graphene nanoplatelets; ion irradiation; molecular dynamics; trapping yield