Electrical transport measurements were carried out on a ceramic samples of La0.5Pb0.5MnO3 containing 10 at.% of Ag in a dispersed form and La0.8Sr0.2MnO3. Their resistivity at zero applied magnetic field exhibits a shallow minimum at the interval of T∼25-30 K. This minimum shifts towards lower T upon applying a magnetic field (H) and disappears at a certain field Hcr, while residual resistivity decreases notably with increasing of H. It is found that the bulk-scattering model is not adequate for describing of such behavior of ρ in the presence of H. It seems that the proposed model of charge-carrier tunneling between antiferromagnetically coupled grains accounts for the results obtained in spite of significant difference in the crystallinity (grain size) of the samples.
|Number of pages||4|
|Journal||Journal of Alloys and Compounds|
|State||Published - 9 Aug 2001|
|Event||Proceedings of the International on Magnetic Materials - Calcutta, India|
Duration: 17 Oct 2000 → 19 Oct 2000
- Doped La-manganites
- Tunneling resistivity