Effect of carrier doping on the formation and collapse of magnetic polarons in lightly hole-doped La1-xSrxCoO3

Journal Article · Sat Jan 01 04:00:00 EST 2011 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.83.134430· OSTI ID:1015024

Podlesnyak, Andrey A ^[1]; Ehlers, Georg ^[1]; Frontzek, Matthias D ^[1]; Sefat, A. S. ^[2]; Furrer, Albert ^[3]; Straessle, Thierry ^[3]; Pomjakushina, Ekaterina ^[4]; Conder, Kazimierz ^[4]; Demmel, F. ^[5]; Khomskii, D. I. ^[6]

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1. ORNL
2. Oak Ridge National Laboratory (ORNL)
3. Laboratory for Neutron Scattering ETHZ & PSI
4. Paul Scherrer Institut, Villigen, Switzerland
5. ISIS Facility, Rutherford Appleton Laboratory
6. Universitat zu Koln, Koln, Germany

We investigate the doping dependence of the nanoscale electronic and magnetic inhomogeneities in the hole-doping range 0.002 < x < 0.1 of cobalt based perovskites, La{sub 1-x}Sr{sub x}CoO{sub 3}. Using single-crystal inelastic neutron scattering and magnetization measurements we show that the lightly doped system exhibits magnetoelectronic phase separation in the form of spin-state polarons. Higher hole doping leads to a decay of spin-state polarons in favor of larger scale magnetic clusters, due to competing ferromagnetic correlations of Co{sup 3+} ions which are formed by neighboring polarons. The present data give evidence for two regimes of magnetoelectronic phase separation in this system: (i) x {approx}< 0.05, dominated by ferromagnetic intrapolaron interactions, and (ii) x {approx}> 0.05, dominated by Co{sup 3+}-Co{sup 3+} intracluster interactions. Our conclusions are in good agreement with a recently proposed model of the phase separation in cobalt perovskites.

• Research Organization: Oak Ridge National Laboratory (ORNL); Spallation Neutron Source
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1015024
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 13 Vol. 83; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COBALT
DECAY
MAGNETIZATION
NEUTRONS
PEROVSKITES
POLARONS
SCATTERING