Signatures of electronic polarons in La1-xSr 1+xMnO4 observed by electron energy-loss spectroscopy
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Contributors
Abstract
The dielectric properties of La1-xSr1+xMnO 4 single crystals with x= 0, 0.125, 0.25, and 0.5 were studied by means of electron energy-loss spectroscopy as a function of temperature and momentum transfer. A clear signature of the doped holes is observed around 1.65 eV energy loss, where spectral weight emerges with increasing x. For all x 0, this doping-induced excitation can propagate within the ab-plane, as revealed by a clear upward dispersion of the corresponding loss peak with increasing momentum transfer. The hole-induced excitation also shifts to higher energies with the onset of magnetic correlations for x=0.5, implying a strong coupling of charge and spin dynamics. We conclude that (i) the loss feature at 1.65 eV is a signature of electronic polarons, which are created around doped holes and that (ii) this low-energy excitation involves the charge transfer between manganese and oxygen. The finite dispersion of these excitations further indicates significant polaron-polaron interactions.
Details
Original language | English |
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Article number | 165130 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 83 |
Issue number | 16 |
Publication status | Published - 29 Apr 2011 |
Peer-reviewed | Yes |
External IDs
ORCID | /0000-0002-2438-0672/work/158767790 |
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