title: High energy-resolution electron energy-loss spectroscopy study of the electronic structures of Li- and Mg-doped alpha-rhombohedral boron.
abstract: Electron-doped alpha-rhombohedral boron (alpha-r-B) crystals were synthesized by Li- and Mg-dopings. The doped alpha-r-B particles showed a shiny metallic colour, though non-doped alpha-r-B crystals showed a dark red colour (red boron). The electronic structures of doped alpha-r-B single crystals were examined by a high energy-resolution electron energy-loss spectroscopy microscope. Boron 1s electron-excitation spectra, which show the density of states of the conduction bands, of Li-doped alpha-r-B showed a chemical shift toward a smaller binding-energy side, indicating a charge transfer from the doped atoms to alpha-r-B. These spectra also showed a sharp intensity increase at the onset with a width of an energy resolution of the experiment. The sharp intensity increase may be assigned to a Fermi edge produced by the electron doping. The spectra of Mg-doped alpha-r-B showed a chemical shift indicating an electron doping, but did not show the presence of a Fermi edge.
authors.affiliation: Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Terauchi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Oguri
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kimura
authors.forename: Akihiko
authors.initials: A
authors.lastname: Fujiwara
mesh_terms: D001895:Boron / Q000737:chemistry*; D003461:Crystallography; D008094:Lithium / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D046590:Spectroscopy, Electron Energy-Loss
chemical_list: D008094:Lithium; D008274:Magnesium; D001895:Boron