title: Discovery of the Pt-Based Superconductor LaPt5As.
abstract: A novel superconductor, LaPt5As, which exhibits a new crystal structure was discovered by high-pressure synthesis using a Kawai-type apparatus. A superconducting transition temperature was observed at 2.6 K. Depending on the sintering pressure, LaPt5As has superconducting and non-superconducting phases with different crystal structures. A sintering pressure of around 10 GPa is effective to form single-phase superconducting LaPt5As. This material has a very unique crystal structure with an extremely long c lattice parameter of over 60 Å and corner-sharing tetrahedrons composed of network-like Pt layers. Density functional theory calculations have suggested that the superconducting current flows through these Pt layers. Also, this unique layered structure characteristic of LaPt5As is thought to play a key role in the emergence of superconductivity. Furthermore, due to a stacking structure which makes up layers, various structural modifications for the LaPt5As family are conceivable. Since such a high-pressure synthesis using a Kawai-type apparatus is not common in the field of materials science, there is large room for further exploration of unknown phases which are induced by high pressure in various materials.
authors.affiliation: Research Institute for Electronic Science, Hokkaido University , Sapporo, Hokkaido 001-0020, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Fujioka
authors.affiliation: Department of Materials Science and Engineering, Kyushu Institute of Technology , Tobata, Kitakyushu, Fukuoka 804-8550, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Ishimaru
authors.affiliation: IoT Devices Research Laboratories, NEC Corporation , Tsukuba, Ibaraki 305-8501, Japan.
authors.forename: Taizo
authors.initials: T
authors.lastname: Shibuya
authors.affiliation: Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University , Yokohama, Kanagawa 223-8522, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kamihara
authors.affiliation: Graduate School of Science, Hokkaido University , Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Tabata
authors.affiliation: Graduate School of Science, Hokkaido University , Sapporo, Hokkaido 060-0810, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Amitsuka
authors.affiliation: Faculty of Engineering, Hokkaido University , Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Miura
authors.affiliation: MANA, National Institute for Materials Science , 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: MANA, National Institute for Materials Science , 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Takano
authors.affiliation: Research Institute for Electronic Science, Hokkaido University , Sapporo, Hokkaido 001-0020, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Kaiju
authors.affiliation: Research Institute for Electronic Science, Hokkaido University , Sapporo, Hokkaido 001-0020, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Nishii