Electrical transport in manganite granular systems
Abstract
A systematic investigation of magnetic and transport properties is carried out for La2/3Ca1/3MnO3 granular system. Based on the magnetization measurement, it is argued that oscillatory indirect magnetic exchange coupling via the boundary material with thickness s sandwiched between the neighboring grains exists in polycrystalline manganites. By introducing a distribution function of s and averaging the conductivity deduced from the spin-polarized tunneling model for the neighboring grains, we obtain a general expression for the temperature dependence of resistance that can reproduce the experimental data observed in polycrystalline manganites. The present model provides information on the microscopic transport mechanism.
- Publication:
-
Physical Review B
- Pub Date:
- November 2003
- DOI:
- 10.1103/PhysRevB.68.184423
- Bibcode:
- 2003PhRvB..68r4423Y
- Keywords:
-
- 75.47.Gk;
- 75.70.Cn;
- 72.25.-b;
- Colossal magnetoresistance;
- Magnetic properties of interfaces;
- Spin polarized transport