title: High-density electron anions in a nanoporous single crystal: [Ca24Al28O64]4+(4e-).
abstract: We removed approximately 100% of clathrated oxygen ions from the crystallographic cages in a single crystal of 12CaO.7Al2O3, leading to the formation of high-density (approximately 2 x 10(21) cm-3) electrons highly localized in the cages. The resulting electron forms a structure that we interpret as an F+ center and migrates throughout the crystal by hopping to a neighboring cage with conductivity approximately 100 siemens per centimeter, demonstrating that the encaged electron behaves as an anion. The electron anions couple antiferromagnetically with each other, forming a diamagnetic pair or singlet bipolaron. The resulting [Ca24Al28O64]4+(4e-) may be regarded as a thermally and chemically stable single crystalline "electride."
authors.affiliation: Hosono Transparent and Electro-Active Materials Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Corporation, KSP C-1232, 3-2-1 Sakado, Takatsu-ku, Kawasaki 213-0012, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Matsuishi
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Toda
authors.forename: Masashi
authors.initials: M
authors.lastname: Miyakawa
authors.forename: Katsuro
authors.initials: K
authors.lastname: Hayashi
authors.forename: Toshio
authors.initials: T
authors.lastname: Kamiya
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hirano
authors.forename: Isao
authors.initials: I
authors.lastname: Tanaka
authors.forename: Hideo
authors.initials: H
authors.lastname: Hosono