Signatures of electronic polarons in La1-xSr 1+xMnO4 observed by electron energy-loss spectroscopy

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Roberto Kraus - , Leibniz Institute for Solid State and Materials Research Dresden (Autor:in)
  • Matthias Schrade - , Leibniz Institute for Solid State and Materials Research Dresden (Autor:in)
  • Roman Schuster - , Leibniz Institute for Solid State and Materials Research Dresden (Autor:in)
  • Martin Knupfer - , Leibniz Institute for Solid State and Materials Research Dresden (Autor:in)
  • Alexandre Revcolevschi - , Université Paris-Saclay (Autor:in)
  • Bernd Büchner - , Professur für Experimentelle Festkörperphysik (gB/IFW), Leibniz Institute for Solid State and Materials Research Dresden (Autor:in)
  • Jochen Geck - , Leibniz Institute for Solid State and Materials Research Dresden (Autor:in)

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

OriginalspracheEnglisch
Aufsatznummer165130
FachzeitschriftPhysical Review B - Condensed Matter and Materials Physics
Jahrgang83
Ausgabenummer16
PublikationsstatusVeröffentlicht - 29 Apr. 2011
Peer-Review-StatusJa

Externe IDs

ORCID /0000-0002-2438-0672/work/158767790