High Temperature Electronic Structure Changes and Polaronic Behavior In Colossal Magnetoresistive Manganites
Abstract
A recent multi-spectroscopic study of La1-xSrxMnO (x = 0.3, 0.4) using photoemission, x-ray absorption and x-ray emission has exposed a marked change in the electronic structure on passing TC. The relationship of these data to other recent work suggesting polaron formation at high temperatures, as well as heterogeneity and phase separation, will be discussed. The increase of the Mn spin moment by ca. 1 Bohr magneton, together with charge transfer onto the Mn and the presence of local Jahn-Teller distortions at high T provides direct evidence of lattice polaron formation. Additional measurements of magnetic susceptibility further suggest the formation of ferromagnetic clusters in the metallic paramagnetic state. These results thus challenge the belief of some authors that the LSMO compounds are canonical double-exchange (DE) systems in which polaron formation is unimportant, and thus help to unify the theoretical description of the CMR oxides.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARL24013M