title: Iron arsenides with three-dimensional FeAs layer networks: Can(n+1)/2(Fe1-xPtx)(2+3n)Ptn(n-1)/2As(n+1)(n+2)/2(n = 2, 3).
abstract: We report the comprehensive studies between synchrotron X-ray diffraction, electrical resistivity and magnetic susceptibility experiments for the iron arsenides Can(n+1)/2(Fe1-xPtx)(2+3n)Ptn(n-1)/2As(n+1)(n+2)/2for n = 2 and 3. Both structures crystallize in the monoclinic space group P21/m (#11) with three-dimensional FeAs structures. The horizontal FeAs layers are bridged by inclined FeAs planes through edge-sharing FeAs5 square pyramids, resulting in triangular tunneling structures rather than the simple layered structures found in conventional iron arsenides. n = 3 system shows a sign of superconductivity with a small volume fraction. Our first-principles calculations of these systems clearly indicate that the Fermi surfaces originate from strong Fe-3d characters and the three-dimensional nature of the electric structures for both systems, thus offering the playgrounds to study the effects of dimensionality on high Tcsuperconductivity.
authors.affiliation: Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Katayama
authors.affiliation: Department of Physics, Okayama University, Okayama 700-8530, Japan.
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Onari
authors.affiliation: Department of Engineering Science, University of Electro-Communications, Chofu, Tokyo 182-8585, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Matsubayashi
authors.affiliation: Institute for Solid State Physics, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Uwatoko
authors.affiliation: Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sawa