Spin-state polarons in lightly hole-doped LaCoO3

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.101.247603· OSTI ID:944105

Podlesnyak, Andrey A ^[1]; Russina, Margarita ^[2]; Furrer, Albert ^[3]; Alfonsov, Aleksei ^[4]; Vavilova, Eugenia ^[4]; Kataev, Vladislav ^[4]; Buechner, Bernd ^[4]; Straessle, Thierry ^[3]; Pomjakushina, Ekaterina ^[5]; Conder, Kazimierz ^[5]; Khomskii, Daniel ^[6]

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1. ORNL
2. Hahn-Meitner Institut, Berlin, Germany
3. Laboratory for Neutron Scattering ETHZ & PSI
4. IFW Dresden
5. Paul Scherrer Institut, Villigen, Switzerland
6. Universitat zu Koln, Koln, Germany

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 La{sub 1-x}Sr{sub x}CoO{sub 3}, x{approx}0.002. Both INS and ESR low temperature spectra show intense excitations with large effective g factors {approx}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 Co{sup 3+} ions.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 944105
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 24 Vol. 101; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ELECTRON SPIN RESONANCE
NEUTRONS
NUCLEAR MAGNETIC RESONANCE
ORIGIN
POLARONS
SCATTERING
SPECTRA
SPIN