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Spectacular doping dependence of interlayer exchange and other results on spin waves in bilayer manganites

T. G. Perring·D. T. Adroja·G. Chaboussant·G. Aeppli·T. Kimura·Y. Tokura
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Abstract

We report the measurement of spin waves in the bilayer colossal magnetoresistive manganites La(2-2x)Sr(1+2x)Mn2O7 with x=0.30, 0.35 and 0.40. For x=0.35 and 0.40 the entire acoustic and optic dispersion relations are reasonably well described by those for a bilayer Heisenberg Hamiltonian with nearest neighbour exchange only. The in-plane coupling is only weakly dependent on x, but the coupling between the planes of a bilayer changes by a factor of four. The results directly reveal the change from mixed and character of the orbitals to mostly character with increasing hole concentration.

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T. G. Perring, D. T. Adroja, G. Chaboussant, G. Aeppli, T. Kimura, Y. Tokura. 2001-05-11. Spectacular doping dependence of interlayer exchange and other results on spin waves in bilayer manganites. https://doi.org/10.1103/physrevlett.87.217201

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