title: Synthesis of borophenes: Anisotropic, two-dimensional boron polymorphs.
abstract: At the atomic-cluster scale, pure boron is markedly similar to carbon, forming simple planar molecules and cage-like fullerenes. Theoretical studies predict that two-dimensional (2D) boron sheets will adopt an atomic configuration similar to that of boron atomic clusters. We synthesized atomically thin, crystalline 2D boron sheets (i.e., borophene) on silver surfaces under ultrahigh-vacuum conditions. Atomic-scale characterization, supported by theoretical calculations, revealed structures reminiscent of fused boron clusters with multiple scales of anisotropic, out-of-plane buckling. Unlike bulk boron allotropes, borophene shows metallic characteristics that are consistent with predictions of a highly anisotropic, 2D metal.
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Building 440, Argonne, IL 60439, USA. Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Mannix
authors.affiliation: Department of Geosciences, Center for Materials by Design, and Institute for Advanced Computational Science, Stony Brook University, Stony Brook, NY 11794, USA. School of Physics, Nankai University, Tianjin 300071, China.
authors.forename: Xiang-Feng
authors.initials: XF
authors.lastname: Zhou
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Building 440, Argonne, IL 60439, USA. Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Kiraly
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Wood
authors.affiliation: Department of Physics, University of Texas San Antonio, San Antonio, TX 78249, USA.
authors.forename: Diego
authors.initials: D
authors.lastname: Alducin
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA. NUANCE Center, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Myers
authors.affiliation: Applied Physics Graduate Program, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Liu
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Building 440, Argonne, IL 60439, USA.
authors.forename: Brandon L
authors.initials: BL
authors.lastname: Fisher
authors.affiliation: Department of Physics, University of Texas San Antonio, San Antonio, TX 78249, USA.
authors.forename: Ulises
authors.initials: U
authors.lastname: Santiago
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Building 440, Argonne, IL 60439, USA.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Guest
authors.affiliation: Department of Physics, University of Texas San Antonio, San Antonio, TX 78249, USA.
authors.forename: Miguel Jose
authors.initials: MJ
authors.lastname: Yacaman
authors.affiliation: Department of Physics, University of Texas San Antonio, San Antonio, TX 78249, USA.
authors.forename: Arturo
authors.initials: A
authors.lastname: Ponce
authors.affiliation: Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, 5 Nobel Street, Moscow 143026, Russia. Moscow Institute of Physics and Technology, 9 Institutskiy Lane, Dolgoprudny City, Moscow Region, 141700, Russia. Department of Geosciences, Center for Materials by Design, and Institute for Advanced Computational Science, Stony Brook University, Stony Brook, NY 11794, USA. nguisinger@anl.gov m-hersam@northwestern.edu artem.oganov@stonybrook.edu.
authors.forename: Artem R
authors.initials: AR
authors.lastname: Oganov
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA. Applied Physics Graduate Program, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA. Department of Chemistry, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA. nguisinger@anl.gov m-hersam@northwestern.edu artem.oganov@stonybrook.edu.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Hersam
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Building 440, Argonne, IL 60439, USA. nguisinger@anl.gov m-hersam@northwestern.edu artem.oganov@stonybrook.edu.
authors.forename: Nathan P
authors.initials: NP
authors.lastname: Guisinger
mesh_terms: D016880:Anisotropy; D001895:Boron / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D014618:Vacuum
chemical_list: D037741:Fullerenes; D012834:Silver; D001895:Boron