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.
Spatial crossover of polarons across the CMR transition in La0.75Ca0.25MnO3 system / A., Lanzara; F., Natali; Saini, Naurang Lal; Bianconi, Antonio; P. G., Radaelli. - In: JOURNAL OF SYNCHROTRON RADIATION. - ISSN 0909-0495. - STAMPA. - 6:(1999), pp. 776-778. [10.1107/S090904959801735X]
Spatial crossover of polarons across the CMR transition in La0.75Ca0.25MnO3 system
SAINI, Naurang Lal;BIANCONI, Antonio;
1999
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
