https://doi.org/10.1140/epjb/e2003-00068-8
Insulator-metal transition shift related to magnetic polarons in La0.67-xYxCa0.33MnO3
Structure Research Laboratory, Department of Materials Science and Engineering,
University of Science and Technology of China, Hefei 230026, PR China
Corresponding author: a lixg@ustc.edu.cn
Received:
27
August
2002
Revised:
2
December
2002
Published online:
14
March
2003
The magnetic transport properties have been measured for La0.67-xYxCa0.33MnO3 () system. It was found that the transition temperature Tp almost linearly moves to
higher temperature as H increases. Electron spin resonance confirms that above Tp, there
exist ferromagnetic clusters. From the magnetic polaron point of view, the shift of Tp
vs.
H
was understood, and it was estimated that the size of the magnetic polaron is of 9.7~15.4 Å which is consistent with the magnetic correlation length revealed by the small-angle
neutron-scattering technique. The transport properties at temperatures higher than Tp
conform to the variable-range hopping mechanism.
PACS: 75.30.Vn – Colossal magnetoresistance / 71.30.+h – Metal-insulator transitions and other electronic transitions / 76.30.-v – Electron paramagnetic resonance and relaxation
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003