title: Superconductivity in Ca10(Ir4As8)(Fe2As2)5 with Square-Planar Coordination of Iridium.
abstract: We report the unprecedented square-planar coordination of iridium in the iron iridium arsenide Ca(10)(Ir(4)As(8))(Fe(2)As(2))5. This material experiences superconductivity at 16 K. X-ray photoemission spectroscopy and first-principles band calculation suggest Ir(II) oxidation state, which yields electrically conductive Ir(4)As(8) layers. Such metallic spacer layers are thought to enhance the interlayer coupling of Fe(2)As(2), in which superconductivity emerges, thus offering a way to control the superconducting transition temperature.
authors.affiliation: Department of Physics, Okayama University, Okayama 700-8530, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Kudo
authors.forename: Daisuke
authors.initials: D
authors.lastname: Mitsuoka
authors.forename: Masaya
authors.initials: M
authors.lastname: Takasuga
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Kento
authors.initials: K
authors.lastname: Sugawara
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Katayama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sawa
authors.forename: Hiroaki S
authors.initials: HS
authors.lastname: Kubo
authors.forename: Kenta
authors.initials: K
authors.lastname: Takamori
authors.forename: Masanori
authors.initials: M
authors.lastname: Ichioka
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Fujii
authors.forename: Takashi
authors.initials: T
authors.lastname: Mizokawa
authors.forename: Minoru
authors.initials: M
authors.lastname: Nohara