title: Site occupancy and magnetic properties of pyrochlore-structured AgOs2O6.
abstract: AgOs(2)O(6) prepared from ion-exchanged superconducting β-pyrochlore KOs(2)O(6) has been shown to be non-superconducting. Synchrotron x-ray structure refinement suggests that AgOs(2)O(6) has the Ag ion mostly occupying the low-symmetry 32e site in the [Formula: see text] space group of proper occupancy, which is different from the original major occupancy at the high-symmetry 8b site for KOs(2)O(6), and similar to non-superconducting Na(1.4)Os(2)O(6)·H(2)O. Magnetic susceptibility measurements found no magnetic ordering down to ~1.7 K. The trace amount of isolated spins suggests that the Ag could be neutral and lead to a pure Os(6+) valence state of zero spin in the newly prepared AgOs(2)O(6).
authors.affiliation: Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: G J
authors.initials: GJ
authors.lastname: Shu
authors.forename: S L
authors.initials: SL
authors.lastname: Hsu
authors.forename: M-W
authors.initials: MW
authors.lastname: Chu
authors.forename: C C
authors.initials: CC
authors.lastname: Lee
authors.forename: F C
authors.initials: FC
authors.lastname: Chou