Spatial cross-over of polarons across the CMR transition in La0.75Ca0.25MnO3 system.

We have measured high resolution Mn K-edge x-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) to investigate the local atomic displacements in the MnO6 octahedra and their importance to the colossal magnetoresistance in the La0.75Ca0.25MnO3 system. A co...

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Bibliographic Details
Main Authors: Lanzara, A, Natoli, F, Saini, N, Bianconi, A, Radaelli, P
Format: Journal article
Language:English
Published: 1999
Description
Summary:We have measured high resolution Mn K-edge x-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) to investigate the local atomic displacements in the MnO6 octahedra and their importance to the colossal magnetoresistance in the La0.75Ca0.25MnO3 system. A combined analysis of the XANES and EXAFS shows that the colossal-magneto resistance (CMR) transition is characterized by a transition from a phase of delocalized intermediate polarons to a phase showing coexistence of the intermediate and small polarons accompanied by the opening of a gap at EF due to Jahn Teller splitting of eg orbitals.