Spin-state polaron in lightly hole-doped LaCoO_3

Podlesnyak, A.; Russina, M.; Furrer, A.; Alfonsov, A.; Vavilova, E.; Kataev, V.; Büchner, B.; Strässle, Th.; Pomjakushina, E.; Conder, K.; Khomskii, D. I.

Spin-state polaron in lightly hole-doped LaCoO_3

Authors

Description

Inelastic neutron scattering (INS), electron spin (ESR) and nuclear magnetic resonance (NMR) measurements were employed to establish the origin of the strong magnetic signal in lightly hole-doped La_{1-x}Sr_xCoO_3, x=0.002. Both, INS and ESR low temperature spectra show intense excitations with large effective g-factors ~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.
10 pages, 3 figures