Abstract
A slight minimum in the zero-field resistivity of a single crystalline La0.8Sr0.2MnO3 and shallow one for ceramic La0.8Sr0.2MnO3 samples were observed at T∼4 K and at T∼25-30 K, respectively. The minimum for the ceramic shifts towards lower temperatures, flattens with increasing magnetic fields (H), and vanishes at some critical H. The above effects are accompanied by an appreciable negative magnetoresistance (MR). On the other hand, the minimum for the single-crystalline sample is almost field independent and the MR in the relevant temperature range is very small. Two different mechanisms were found to account for the results observed in the single crystal and the polycrystalline samples: (i) mesoscopic corrections to the bulk resistivity that include Coulomb interaction and weak localization and (ii) intergranular tunneling. The resistivity of the large-grain ceramic sample comprises both types of behavior. The minimum of the bulk contribution becomes clearly seen under H, which suppresses the ceramic-type minimum.
Original language | English |
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Pages (from-to) | 6639-6641 |
Number of pages | 3 |
Journal | Journal of Applied Physics |
Volume | 89 |
Issue number | 11 II |
DOIs | |
State | Published - 1 Jun 2001 |
Event | 8th Joint Magnetism and Magnetic Materials-Intermag Conference - San Antonio, TX, United States Duration: 7 Jan 2001 → 11 Jan 2001 |
ASJC Scopus subject areas
- General Physics and Astronomy