title: Spin-state polarons in lightly-hole-doped LaCoO3.
abstract: Inelastic neutron scattering (INS), electron spin resonance (ESR), and nuclear magnetic resonance (NMR) measurements were employed to establish the origin of the strong magnetic signal in lightly-hole-doped La1-xSrxCoO3, x approximately 0.002. Both INS and ESR low temperature spectra show intense excitations with large effective g factors approximately 10-18. NMR data indicate the creation of extended magnetic clusters. From the Q dependence of the INS magnetic intensity, we conclude that the observed anomalies are caused by the formation of octahedrally shaped spin-state polarons comprising seven Co ions. The present INS, ESR, and NMR data give evidence for two regimes in the lightly-hole-doped samples: (i) T<35 K dominated by spin polarons; (ii) T>35 K dominated by thermally activated magnetic Co3+ ions.
authors.affiliation: Hahn-Meitner-Institut, Glienicker Strasse 100, Berlin 14109, Germany. podlesnyakaa@ornl.gov
authors.forename: A
authors.initials: A
authors.lastname: Podlesnyak
authors.forename: M
authors.initials: M
authors.lastname: Russina
authors.forename: A
authors.initials: A
authors.lastname: Furrer
authors.forename: A
authors.initials: A
authors.lastname: Alfonsov
authors.forename: E
authors.initials: E
authors.lastname: Vavilova
authors.forename: V
authors.initials: V
authors.lastname: Kataev
authors.forename: B
authors.initials: B
authors.lastname: Büchner
authors.forename: Th
authors.initials: T
authors.lastname: Strässle
authors.forename: E
authors.initials: E
authors.lastname: Pomjakushina
authors.forename: K
authors.initials: K
authors.lastname: Conder
authors.forename: D I
authors.initials: DI
authors.lastname: Khomskii