title: Site-dependent cobalt electronic state in La-Co co-substituted magnetoplumbite-type ferrite: (59)Co nuclear magnetic resonance study.
abstract: The nuclear magnetic resonance of (59)Co was measured over a wide frequency range in a powder sample crushed from a well-characterized single crystal of La-Co co-substituted magnetoplumbite-type strontium ferrite (SrFe12O19), a familiar base material for the ferrite permanent magnet. The simultaneous observation of both high- and low-frequency resonances suggests the coexistence of both high- and low-spin states of the substituted Co or the presence of Co orbital moment at a particular site. The possible presence of trivalent Co was also investigated. The results suggest that the Co atoms are distributed across different crystallographic sites with different local environments, and that the electronic state of Co is much more subtle than the conventional understanding.
authors.affiliation: Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Aiko
authors.initials: A
authors.lastname: Shimoda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Waki
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Tabata
authors.forename: Christian
authors.initials: C
authors.lastname: Mény