Spin-state polarons in lightly-hole-doped LaCoO3.
Phys Rev Lett
; 101(24): 247603, 2008 Dec 12.
Article
em En
| MEDLINE
| ID: mdl-19113665
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.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Alemanha