A quantitative determination of the statistical distribution of the Mn-O instantaneous bond lengths in the La0.75Ca0.25MnO3 system by Mn K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy shows that the giant magneto-resistance (GMR) transition occurs at a crossover from a metallic phase with large (or intermediate) polarons to an insulating phase where small polarons coexist with large (or intermediate) polarons. In the GMR region, the two Mn polaronic domains coexist and share half of the space.
A transition from large to small polarons in the La0.75Ca0.25MnO3 perovskite system / A., Lanzara; Saini, Naurang Lal; M., Brunelli; F., Natali; Bianconi, Antonio; P., Radaelli; S. W., Cheong. - In: JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS. - ISSN 0022-3697. - STAMPA. - 59:(1998), pp. 2220-2223. [10.1016/S0022-3697(98)00218-2]
A transition from large to small polarons in the La0.75Ca0.25MnO3 perovskite system
SAINI, Naurang Lal;BIANCONI, Antonio;
1998
Abstract
A quantitative determination of the statistical distribution of the Mn-O instantaneous bond lengths in the La0.75Ca0.25MnO3 system by Mn K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy shows that the giant magneto-resistance (GMR) transition occurs at a crossover from a metallic phase with large (or intermediate) polarons to an insulating phase where small polarons coexist with large (or intermediate) polarons. In the GMR region, the two Mn polaronic domains coexist and share half of the space.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
