Electronic Resource
Woodbury, NY
:
American Institute of Physics (AIP)
Applied Physics Letters
81 (2002), S. 319-321
ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
We present a study of the magnetotransport behavior around Tc of epitaxial La0.7Ca0.3MnO3 thin films with controlled chemical defects introduced in order to change the electron-lattice coupling (λ). We found unexpected enhancement of the very low field (below 250 Oe) magnetoresistance around Tc and relate it to a reduction of the magnetic domain size. This process is strongly favored by the presence of chemical defects that also promote weak localization of the carriers into polaron clusters that can be overcome by relatively low magnetic fields. This behavior is characteristic of temperatures near Tc where the bandwidth is reduced and localization, due to intrinsic disorder and chemical defects, is more probable. In addition, the increase of λ raises the polaron binding energy and reduces the temperature at which percolation occurs. © 2002 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1491602
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