title: Superconductivity in room-temperature stable electride and high-pressure phases of alkali metals.
abstract: S-band metals such as alkali and alkaline earth metals do not undergo a superconducting transition (SCT) at ambient pressure, but their high-pressure phases do. By contrast, room-temperature stable electride [Ca(24)Al(28)O(64)](4+)⋅4e(-) (C12A7:e(-)) in which anionic electrons in the crystallographic sub-nanometer-size cages have high s-character exhibits SCT at 0.2-0.4 K at ambient pressure. In this paper, we report that crystal and electronic structures of C12A7:e(-) are close to those of the high-pressure superconducting phase of alkali and alkaline earth metals and the SCT of both materials is induced when electron nature at Fermi energy (EF) switches from s- to sd-hybridized state.
authors: Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503, Japan ACCEL Program, Japan Science and Technology Agency (JST), Hon-cho, Kawaguchi 332-0012, Japan hosono@msl.titech.ac.jp.
authors: Hideo
authors: H
authors: Hosono
authors: Department of Energy Science, Sungkyunkwan Unversity, Suwan 440-746, Korea kimsungwng@skku.edu.
authors: Sung-Wng
authors: SW
authors: Kim
authors: Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503, Japan.
authors: Satoru
authors: S
authors: Matsuishi
authors: Center for Quantum Science and Technology under Extreme Conditions, Osaka University, Toyonaka 560-8531, Japan.
authors: Shigeki
authors: S
authors: Tanaka
authors: Center for Quantum Science and Technology under Extreme Conditions, Osaka University, Toyonaka 560-8531, Japan.
authors: Atsushi
authors: A
authors: Miyake
authors: Center for Quantum Science and Technology under Extreme Conditions, Osaka University, Toyonaka 560-8531, Japan.
authors: Tomoko
authors: T
authors: Kagayama
authors: Center for Quantum Science and Technology under Extreme Conditions, Osaka University, Toyonaka 560-8531, Japan.
authors: Katsuya
authors: K
authors: Shimizu
keywords: alkali metal; electride; electronic state; high pressure; superconductivity